If possible, try to scan your vehicle. You can read your check engine light with or without a scanner and get an exact diagnosis rather than rely only on your powers of deduction.
But, if you are on the side of the road and in a rush, this list of common causes for each Hyundai model should help you narrow down the most likely cause of your issue.
Take a look through the tables below for the most common causes for your Hyundai models’ Check Engine Light. If none of the causes below match the symptoms you’re experiencing or if you want a more in depth explanation of the common causes, go ahead and check out “The 13 Most Common Causes For A Check Engine Light | How To Diagnose Them”.
Let’s dive in.
Mercedes-Benz C230 CEL – Causes, Diagnostic Codes, Potential Repairs, & Repair Costs
DTC Codes | Most Common Causes | Repair | Repair Cost | |
#1 | Dirty mass airflow sensor | Clean mass airflow sensor | Clean mass airflow sensor: $20 – $100 | |
Faulty mass airflow sensor | Replace mass airflow sensor | Replace mass airflow sensor: $230 – $330 | ||
Vacuum leaks – PCV hoses, vacuum hoses, intake manifold gasket | Seal vacuum leak | Vacuum leak $100 – $200 | ||
#2 | Dirty mass airflow sensor | Clean mass airflow sensor | Clean mass airflow sensor: $20 – $100 | |
Faulty mass airflow sensor | Replace mass airflow sensor | Replace mass airflow sensor: $230 – $330 | ||
Vacuum leaks – PCV hoses, vacuum hoses, intake manifold gasket | Seal vacuum leak | Vacuum leak: $100 – $200 | ||
Clogged fuel injectors | Clean fuel injectors | Clean fuel injectors: $50 – $80 | ||
#3 | Faulty engine coolant thermostat | Replace engine coolant thermostat | Replace engine coolant thermostat: $40 – $190 | |
#4 | Blown air injector fuse | Replace air injector fuse | Fuse: $10 | |
Faulty air pump | Replace air pump | Air Pump: $570-$710 | ||
Faulty air pump relay | Replace air pump relay | Air Pump Relay: $50-$75 | ||
#5 | Spark plug #1 is worn or broken | Replace spark plug #1 | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 |
Mercedes-Benz C240 CEL – Causes, Diagnostic Codes, Potential Repairs, & Repair Costs
DTC Codes | Most Common Causes | Repair | Repair Cost | |
#1 | Spark plug is worn or broken | Replace spark plugs | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 | ||
#2 | Dirty mass airflow sensor | Clean mass airflow sensor | Clean mass airflow sensor: $20 – $100 | |
Faulty mass airflow sensor | Replace mass airflow sensor | Replace mass airflow sensor: $230 – $330 | ||
Vacuum leaks – PCV hoses, vacuum hoses, intake manifold gasket | Seal vacuum leak | Vacuum leak $100 – $200 | ||
#3 | Blown air injector fuse | Replace air injector fuse | Fuse: $10 | |
Faulty air pump | Replace air pump | Air Pump: $570-$710 | ||
Faulty air pump relay | Replace air pump relay | Air Pump Relay: $50-$75 | ||
#4 | Dirty mass airflow sensor | Clean mass airflow sensor | Clean mass airflow sensor: $20 – $100 | |
Faulty mass airflow sensor | Replace mass airflow sensor | Replace mass airflow sensor: $230 – $330 | ||
Vacuum leaks – PCV hoses, vacuum hoses, intake manifold gasket | Seal vacuum leak | Vacuum leak: $100 – $200 | ||
Clogged fuel injectors | Clean fuel injectors | Clean fuel injectors: $50 – $80 |
Mercedes-Benz C250 CEL – Causes, Diagnostic Codes, Potential Repairs, & Repair Costs
DTC Codes | Most Common Causes | Repair | Repair Cost | |
#1 | Faulty camshaft position sensor | Replace camshaft position sensor | Camshaft position sensor $120-$300 | |
Faulty crankshaft position sensor | Replace crankshaft position sensor | Crankshaft position sensor $190-$250 | ||
Faulty ECM | Replace ECM | ECM $1000-$1200 | ||
Faulty timing chain or belt replacement | Replace timing chain or belt replacement | Timing chain or belt replacement $200-$1000 | ||
#2 | Damaged charcoal cannister | Replace charcoal cannister | Replace charcoal cannister: $753 – $1000 | |
Loose or missing gas cap | Replace or tighten gas cap | Replace or tighten gas cap: $0 – $20 | ||
Faulty purge valve | Replace purge valve | Replace purge valve: $109 – $172 | ||
#3 | Spark plug #4 is worn or broken | Replace spark plug #4 | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 | ||
#4 | Spark plug #3 is worn or broken | Replace spark plug #3 | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 |
Mercedes-Benz C280 CEL – Causes, Diagnostic Codes, Potential Repairs, & Repair Costs
DTC Codes | Most Common Causes | Repair | Repair Cost | |
#1 | Spark plug is worn or broken | Replace spark plugs | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 | ||
#2 | P2006 | Faulty manifold absolute pressure sensor | Replace manifold absolute pressure sensor | Manifold absolute pressure sensor: $140 – $170 |
Carbon buildup on intake manifold runner control system | Replace intake manifold runner control system | Intake manifold runner control system: $350 – $600 | ||
#3 | Blown air injector fuse | Replace air injector fuse | Fuse: $10 | |
Faulty air pump | Replace air pump | Air Pump: $570-$710 | ||
Faulty air pump relay | Replace air pump relay | Air Pump Relay: $50-$75 |
Mercedes-Benz C300 CEL – Causes, Diagnostic Codes, Potential Repairs, & Repair Costs
DTC Codes | Most Common Causes | Repair | Repair Cost | |
#1 | Faulty engine coolant thermostat | Replace engine coolant thermostat | Replace engine coolant thermostat: $40 – $190 | |
#2 | Blown air injector fuse | Replace air injector fuse | Fuse: $10 | |
Faulty air pump | Replace air pump | Air Pump: $570-$710 | ||
Faulty air pump relay | Replace air pump relay | Air Pump Relay: $50-$75 | ||
#3 | Spark plug is worn or broken | Replace spark plugs | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 | ||
#4 | Spark plug #1 is worn or broken | Replace spark plug #1 | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 |
Mercedes-Benz C320 CEL – Causes, Diagnostic Codes, Potential Repairs, & Repair Costs
DTC Codes | Most Common Causes | Repair | Repair Cost | |
#1 | P0400 | Stuck EGR valve | Replace the EGR valve | EGR valve: $250 – $350 |
Faulty EGR temperature sensor | Replace the EGR temperature sensor | EGR temperature sensor: $220 – $230 | ||
#2 | Blown air injector fuse | Replace air injector fuse | Fuse: $10 | |
Faulty air pump | Replace air pump | Air Pump: $570-$710 | ||
Faulty air pump relay | Replace air pump relay | Air Pump Relay: $50-$75 | ||
#3 | Spark plug is worn or broken | Replace spark plugs | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 | ||
#4 | Spark plug #1 is worn or broken | Replace spark plug #1 | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 |
Mercedes-Benz C350 CEL – Causes, Diagnostic Codes, Potential Repairs, & Repair Costs
DTC Codes | Most Common Causes | Repair | Repair Cost | |
#1 | Low oil/dirty oil | Get an oil change or add oil | Engine oil and filter change $20-$60 | |
Timing chain is stretched | Replace timing chain | Timing chain: $1,624 to $1,879 | ||
Slipped reluctor ring on the crankshaft | Replace reluctor ring | Reluctor ring $200-$600 | ||
#2 | Faulty engine coolant thermostat | Replace engine coolant thermostat | Replace engine coolant thermostat: $40 – $190 | |
#3 | P2006 | Faulty manifold absolute pressure sensor | Replace manifold absolute pressure sensor | Manifold absolute pressure sensor: $140 – $170 |
Carbon buildup on intake manifold runner control system | Replace intake manifold runner control system | Intake manifold runner control system: $350 – $600 | ||
#4 | Spark plug is worn or broken | Replace spark plugs | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 |
Mercedes-Benz C63 AMG CEL – Causes, Diagnostic Codes, Potential Repairs, & Repair Costs
DTC Codes | Most Common Causes | Repair | Repair Cost | |
#1 | Dirty mass airflow sensor | Clean mass airflow sensor | Clean mass airflow sensor: $20 – $100 | |
Faulty mass airflow sensor | Replace mass airflow sensor | Replace mass airflow sensor: $230 – $330 | ||
Vacuum leaks – PCV hoses, vacuum hoses, intake manifold gasket | Seal vacuum leak | Vacuum leak $100 – $200 | ||
#2 | Dirty mass airflow sensor | Clean mass airflow sensor | Clean mass airflow sensor: $20 – $100 | |
Faulty mass airflow sensor | Replace mass airflow sensor | Replace mass airflow sensor: $230 – $330 | ||
Vacuum leaks – PCV hoses, vacuum hoses, intake manifold gasket | Seal vacuum leak | Vacuum leak: $100 – $200 | ||
Clogged fuel injectors | Clean fuel injectors | Clean fuel injectors: $50 – $80 | ||
#3 | Spark plug #3 is worn or broken | Replace spark plug #3 | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 | ||
#4 | Damaged or worn-out catalytic converter | Replace catalytic converter | Replace catalytic converter: $400-$2400 | |
Broken O2 sensor | Replace downstream O2 sensor | Oxygen sensor replacement: $275-$500 | ||
Exhaust leak | Seal exhaust leak | Exhaust leak: $100-$200 (if welded to repair) |
Mercedes-Benz CL500 CEL – Causes, Diagnostic Codes, Potential Repairs, & Repair Costs
DTC Codes | Most Common Causes | Repair | Repair Cost | |
#1 | Spark plug is worn or broken | Replace spark plugs | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 | ||
#2 | Spark plug #2 is worn or broken | Replace spark plug #2 | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 | ||
#3 | Spark plug #3 is worn or broken | Replace spark plug #3 | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 | ||
#4 | Spark plug #5 is worn or broken | Replace spark plug #5 | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 | ||
#5 | Spark plug #1 is worn or broken | Replace spark plug #1 | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 |
Mercedes-Benz CLK320 CEL – Causes, Diagnostic Codes, Potential Repairs, & Repair Costs
DTC Codes | Most Common Causes | Repair | Repair Cost | |
#1 | P0400 | Stuck EGR valve | Replace the EGR valve | EGR valve: $250 – $350 |
Faulty EGR temperature sensor | Replace the EGR temperature sensor | EGR temperature sensor: $220 – $230 | ||
#2 | Spark plug is worn or broken | Replace spark plugs | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 | ||
#3 |
| Blown air injector fuse | Replace air injector fuse | Fuse: $10 |
Faulty air pump | Replace air pump | Air Pump: $570-$710 | ||
Faulty air pump relay | Replace air pump relay | Air Pump Relay: $50-$75 | ||
#4 | Missing, loose, or damaged gas cap | TIghten or replace gas cap | Missing or damaged gas cap: $0-$20 | |
Leak in EVAP line | Fix leap in EVAP line | EVAP line: $20-$100 | ||
EVAP vent control valve is damaged or stuck | Replace EVAP vent control valve | EVAP vent control valve: $150-$200 | ||
EVAP purge volume control valve is damaged or stuck | Replace EVAP purge volume control valve | Purge volume control valve: $150-$200 |
Mercedes-Benz CLK350 CEL – Causes, Diagnostic Codes, Potential Repairs, & Repair Costs
DTC Codes | Most Common Causes | Repair | Repair Cost | |
#1 | Low oil/dirty oil | Get an oil change or add oil | Engine oil and filter change $20-$60 | |
Timing chain is stretched | Replace timing chain | Timing chain: $1,624 to $1,879 | ||
Slipped reluctor ring on the crankshaft | Replace reluctor ring | Reluctor ring $200-$600 | ||
#2 | P2006 | Faulty manifold absolute pressure sensor | Replace manifold absolute pressure sensor | Manifold absolute pressure sensor: $140 – $170 |
Carbon buildup on intake manifold runner control system | Replace intake manifold runner control system | Intake manifold runner control system: $350 – $600 | ||
#3 | Spark plug #3 is worn or broken | Replace spark plug #3 | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 | ||
#4 | P0017 | Low oil/dirty oil | Get an oil change or add oil | Engine oil and filter change $20-$60 |
Timing chain is stretched | Replace timing chain | Timing chain: $1,624 to $1,879 | ||
Slipped reluctor ring on the crankshaft | Replace reluctor ring | Reluctor ring $200-$600 | ||
#5 | Faulty engine coolant thermostat | Replace engine coolant thermostat | Replace engine coolant thermostat: $40 – $190 |
Mercedes-Benz E320 CEL – Causes, Diagnostic Codes, Potential Repairs, & Repair Costs
DTC Codes | Most Common Causes | Repair | Repair Cost | |
#1 | P0400 | Stuck EGR valve | Replace the EGR valve | EGR valve: $250 – $350 |
Faulty EGR temperature sensor | Replace the EGR temperature sensor | EGR temperature sensor: $220 – $230 | ||
#2 | Blown air injector fuse | Replace air injector fuse | Fuse: $10 | |
Faulty air pump | Replace air pump | Air Pump: $570-$710 | ||
Faulty air pump relay | Replace air pump relay | Air Pump Relay: $50-$75 | ||
#3 | Missing, loose, or damaged gas cap | TIghten or replace gas cap | Missing or damaged gas cap: $0-$20 | |
Leak in EVAP line | Fix leap in EVAP line | EVAP line: $20-$100 | ||
EVAP vent control valve is damaged or stuck | Replace EVAP vent control valve | EVAP vent control valve: $150-$200 | ||
EVAP purge volume control valve is damaged or stuck | Replace EVAP purge volume control valve | Purge volume control valve: $150-$200 | ||
#4 | Spark plug is worn or broken | Replace spark plugs | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 | ||
#5 | Spark plug #4 is worn or broken | Replace spark plug #4 | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 |
Mercedes-Benz E350 CEL – Causes, Diagnostic Codes, Potential Repairs, & Repair Costs
DTC Codes | Most Common Causes | Repair | Repair Cost | |
#1 | Low oil/dirty oil | Get an oil change or add oil | Engine oil and filter change $20-$60 | |
Timing chain is stretched | Replace timing chain | Timing chain: $1,624 to $1,879 | ||
Slipped reluctor ring on the crankshaft | Replace reluctor ring | Reluctor ring $200-$600 | ||
#2 | P0017 | Low oil/dirty oil | Get an oil change or add oil | Engine oil and filter change $20-$60 |
Timing chain is stretched | Replace timing chain | Timing chain: $1,624 to $1,879 | ||
Slipped reluctor ring on the crankshaft | Replace reluctor ring | Reluctor ring $200-$600 | ||
#3 | P2006 | Faulty manifold absolute pressure sensor | Replace manifold absolute pressure sensor | Manifold absolute pressure sensor: $140 – $170 |
Carbon buildup on intake manifold runner control system | Replace intake manifold runner control system | Intake manifold runner control system: $350 – $600 | ||
#4 | Spark plug is worn or broken | Replace spark plugs | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 | ||
#5 | Faulty engine coolant thermostat | Replace engine coolant thermostat | Replace engine coolant thermostat: $40 – $190 |
Mercedes-Benz E420 CEL – Causes, Diagnostic Codes, Potential Repairs, & Repair Costs
DTC Codes | Most Common Causes | Repair | Repair Cost | |
#1 | Missing, loose, or damaged gas cap | TIghten or replace gas cap | Missing or damaged gas cap: $0-$20 | |
Leak in EVAP line | Fix leap in EVAP line | EVAP line: $20-$100 | ||
EVAP vent control valve is damaged or stuck | Replace EVAP vent control valve | EVAP vent control valve: $150-$200 | ||
EVAP purge volume control valve is damaged or stuck | Replace EVAP purge volume control valve | Purge volume control valve: $150-$200 | ||
#2 | P0140 | Faulty oxygen sensor | Replace oxygen sensor | Oxygen sensor: $200 – $300 |
Faulty mass airflow sensor | Replace mass airflow sensor | Mass airflow sensor: $230 – $330 |
Mercedes-Benz E500 CEL – Causes, Diagnostic Codes, Potential Repairs, & Repair Costs
DTC Codes | Most Common Causes | Repair | Repair Cost | |
#1 | Blown air injector fuse | Replace air injector fuse | Fuse: $10 | |
Faulty air pump | Replace air pump | Air Pump: $570-$710 | ||
Faulty air pump relay | Replace air pump relay | Air Pump Relay: $50-$75 | ||
#2 | Missing, loose, or damaged gas cap | TIghten or replace gas cap | Missing or damaged gas cap: $0-$20 | |
Leak in EVAP line | Fix leap in EVAP line | EVAP line: $20-$100 | ||
EVAP vent control valve is damaged or stuck | Replace EVAP vent control valve | EVAP vent control valve: $150-$200 | ||
EVAP purge volume control valve is damaged or stuck | Replace EVAP purge volume control valve | Purge volume control valve: $150-$200 | ||
#3 | Spark plug is worn or broken | Replace spark plugs | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 | ||
#4 | Dirty mass airflow sensor | Clean mass airflow sensor | Clean mass airflow sensor: $20 – $100 | |
Faulty mass airflow sensor | Replace mass airflow sensor | Replace mass airflow sensor: $230 – $330 | ||
Vacuum leaks – PCV hoses, vacuum hoses, intake manifold gasket | Seal vacuum leak | Vacuum leak $100 – $200 | ||
#5 | P0400 | Stuck EGR valve | Replace the EGR valve | EGR valve: $250 – $350 |
Faulty EGR temperature sensor | Replace the EGR temperature sensor | EGR temperature sensor: $220 – $230 |
Mercedes-Benz GL450 CEL – Causes, Diagnostic Codes, Potential Repairs, & Repair Costs
DTC Codes | Most Common Causes | Repair | Repair Cost | |
#1 | Damaged or worn-out catalytic converter | Replace catalytic converter | Replace catalytic converter: $400-$2400 | |
Broken O2 sensor | Replace downstream O2 sensor | Oxygen sensor replacement: $275-$500 | ||
Exhaust leak | Seal exhaust leak | Exhaust leak: $100-$200 (if welded to repair) | ||
#2 | Faulty engine coolant thermostat | Replace engine coolant thermostat | Replace engine coolant thermostat: $40 – $190 | |
#3 | P2006 | Faulty manifold absolute pressure sensor | Replace manifold absolute pressure sensor | Manifold absolute pressure sensor: $140 – $170 |
Carbon buildup on intake manifold runner control system | Replace intake manifold runner control system | Intake manifold runner control system: $350 – $600 | ||
#4 | Damaged or worn out catalytic converter | Replace catalytic converter | Replace catalytic converter: $400-$2400 | |
Broken O2 sensor | Replace downstream O2 sensor | Replace catalytic converter: $400-$2400 | ||
Exhaust leak | Seal exhaust leak | Exhaust leak: $100-$200 (if welded to repair) | ||
#5 | Missing, loose, or damaged gas cap | TIghten or replace gas cap | Missing or damaged gas cap: $0-$20 | |
Leak in EVAP line | Fix leap in EVAP line | EVAP line: $20-$100 | ||
EVAP vent control valve is damaged or stuck | Replace EVAP vent control valve | EVAP vent control valve: $150-$200 | ||
EVAP purge volume control valve is damaged or stuck | Replace EVAP purge volume control valve | Purge volume control valve: $150-$200 |
Mercedes-Benz ML320 CEL – Causes, Diagnostic Codes, Potential Repairs, & Repair Costs
DTC Codes | Most Common Causes | Repair | Repair Cost | |
#1 | P0400 | Stuck EGR valve | Replace the EGR valve | EGR valve: $250 – $350 |
Faulty EGR temperature sensor | Replace the EGR temperature sensor | EGR temperature sensor: $220 – $230 | ||
#2 | Spark plug is worn or broken | Replace spark plugs | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 | ||
#3 | Blown air injector fuse | Replace air injector fuse | Fuse: $10 | |
Faulty air pump | Replace air pump | Air Pump: $570-$710 | ||
Faulty air pump relay | Replace air pump relay | Air Pump Relay: $50-$75 | ||
#4 | Spark plug #4 is worn or broken | Replace spark plug #4 | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 | ||
#5 | Missing, loose, or damaged gas cap | TIghten or replace gas cap | Missing or damaged gas cap: $0-$20 | |
Leak in EVAP line | Fix leap in EVAP line | EVAP line: $20-$100 | ||
EVAP vent control valve is damaged or stuck | Replace EVAP vent control valve | EVAP vent control valve: $150-$200 | ||
EVAP purge volume control valve is damaged or stuck | Replace EVAP purge volume control valve | Purge volume control valve: $150-$200 |
Mercedes-Benz ML350 CEL – Causes, Diagnostic Codes, Potential Repairs, & Repair Costs
DTC Codes | Most Common Causes | Repair | Repair Cost | |
#1 | Blown air injector fuse | Replace air injector fuse | Fuse: $10 | |
Faulty air pump | Replace air pump | Air Pump: $570-$710 | ||
Faulty air pump relay | Replace air pump relay | Air Pump Relay: $50-$75 | ||
#2 | Low oil/dirty oil | Get an oil change or add oil | Engine oil and filter change $20-$60 | |
Timing chain is stretched | Replace timing chain | Timing chain: $1,624 to $1,879 | ||
Slipped reluctor ring on the crankshaft | Replace reluctor ring | Reluctor ring $200-$600 | ||
#3 | Faulty engine coolant thermostat | Replace engine coolant thermostat | Replace engine coolant thermostat: $40 – $190 | |
#4 | P0017 | Low oil/dirty oil | Get an oil change or add oil | Engine oil and filter change $20-$60 |
Timing chain is stretched | Replace timing chain | Timing chain: $1,624 to $1,879 | ||
Slipped reluctor ring on the crankshaft | Replace reluctor ring | Reluctor ring $200-$600 | ||
#5 | Missing, loose, or damaged gas cap | TIghten or replace gas cap | Missing or damaged gas cap: $0-$20 | |
Leak in EVAP line | Fix leap in EVAP line | EVAP line: $20-$100 | ||
EVAP vent control valve is damaged or stuck | Replace EVAP vent control valve | EVAP vent control valve: $150-$200 | ||
EVAP purge volume control valve is damaged or stuck | Replace EVAP purge volume control valve | Purge volume control valve: $150-$200 |
Mercedes-Benz ML500 CEL – Causes, Diagnostic Codes, Potential Repairs, & Repair Costs
DTC Codes | Most Common Causes | Repair | Repair Cost | |
#1 | Blown air injector fuse | Replace air injector fuse | Fuse: $10 | |
Faulty air pump | Replace air pump | Air Pump: $570-$710 | ||
Faulty air pump relay | Replace air pump relay | Air Pump Relay: $50-$75 | ||
#2 | P0400 | Stuck EGR valve | Replace the EGR valve | EGR valve: $250 – $350 |
Faulty EGR temperature sensor | Replace the EGR temperature sensor | EGR temperature sensor: $220 – $230 | ||
#3 | Missing, loose, or damaged gas cap | TIghten or replace gas cap | Missing or damaged gas cap: $0-$20 | |
Leak in EVAP line | Fix leap in EVAP line | EVAP line: $20-$100 | ||
EVAP vent control valve is damaged or stuck | Replace EVAP vent control valve | EVAP vent control valve: $150-$200 | ||
EVAP purge volume control valve is damaged or stuck | Replace EVAP purge volume control valve | Purge volume control valve: $150-$200 | ||
#4 | Dirty mass airflow sensor | Clean mass airflow sensor | Clean mass airflow sensor: $20 – $100 | |
Faulty mass airflow sensor | Replace mass airflow sensor | Replace mass airflow sensor: $230 – $330 | ||
Vacuum leaks – PCV hoses, vacuum hoses, intake manifold gasket | Seal vacuum leak | Vacuum leak $100 – $200 |
Mercedes-Benz R350 CEL – Causes, Diagnostic Codes, Potential Repairs, & Repair Costs
DTC Codes | Most Common Causes | Repair | Repair Cost | |
#1 | P2006 | Faulty manifold absolute pressure sensor | Replace manifold absolute pressure sensor | Manifold absolute pressure sensor: $140 – $170 |
Carbon buildup on intake manifold runner control system | Replace intake manifold runner control system | Intake manifold runner control system: $350 – $600 | ||
#2 | Low oil/dirty oil | Get an oil change or add oil | Engine oil and filter change $20-$60 | |
Timing chain is stretched | Replace timing chain | Timing chain: $1,624 to $1,879 | ||
Slipped reluctor ring on the crankshaft | Replace reluctor ring | Reluctor ring $200-$600 | ||
#3 | Spark plug is worn or broken | Replace spark plugs | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 | ||
#4 | P0017 | Low oil/dirty oil | Get an oil change or add oil | Engine oil and filter change $20-$60 |
Timing chain is stretched | Replace timing chain | Timing chain: $1,624 to $1,879 | ||
Slipped reluctor ring on the crankshaft | Replace reluctor ring | Reluctor ring $200-$600 | ||
#5 | Faulty engine coolant thermostat | Replace engine coolant thermostat | Replace engine coolant thermostat: $40 – $190 |
Mercedes-Benz S430 CEL – Causes, Diagnostic Codes, Potential Repairs, & Repair Costs
DTC Codes | Most Common Causes | Repair | Repair Cost | |
#1 | P0400 | Stuck EGR valve | Replace the EGR valve | EGR valve: $250 – $350 |
Faulty EGR temperature sensor | Replace the EGR temperature sensor | EGR temperature sensor: $220 – $230 | ||
#2 | Blown air injector fuse | Replace air injector fuse | Fuse: $10 | |
Faulty air pump | Replace air pump | Air Pump: $570-$710 | ||
Faulty air pump relay | Replace air pump relay | Air Pump Relay: $50-$75 | ||
#3 | Spark plug is worn or broken | Replace spark plugs | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 |
Mercedes-Benz S500 CEL – Causes, Diagnostic Codes, Potential Repairs, & Repair Costs
DTC Codes | Most Common Causes | Repair | Repair Cost | |
#1 | Blown air injector fuse | Replace air injector fuse | Fuse: $10 | |
Faulty air pump | Replace air pump | Air Pump: $570-$710 | ||
Faulty air pump relay | Replace air pump relay | Air Pump Relay: $50-$75 | ||
#2 | Spark plug is worn or broken | Replace spark plugs | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 | ||
#3 | P0400 | Stuck EGR valve | Replace the EGR valve | EGR valve: $250 – $350 |
Faulty EGR temperature sensor | Replace the EGR temperature sensor | EGR temperature sensor: $220 – $230 | ||
#4 | Missing, loose, or damaged gas cap | TIghten or replace gas cap | Missing or damaged gas cap: $0-$20 | |
Leak in EVAP line | Fix leap in EVAP line | EVAP line: $20-$100 | ||
EVAP vent control valve is damaged or stuck | Replace EVAP vent control valve | EVAP vent control valve: $150-$200 | ||
EVAP purge volume control valve is damaged or stuck | Replace EVAP purge volume control valve | Purge volume control valve: $150-$200 | ||
#5 | Spark plug #1 is worn or broken | Replace spark plug #1 | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 |
Mercedes-Benz S550 CEL – Causes, Diagnostic Codes, Potential Repairs, & Repair Costs
DTC Codes | Most Common Causes | Repair | Repair Cost | |
#1 | Spark plug is worn or broken | Replace spark plugs | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 | ||
#2 | Missing, loose, or damaged gas cap | TIghten or replace gas cap | Missing or damaged gas cap: $0-$20 | |
Leak in EVAP line | Fix leap in EVAP line | EVAP line: $20-$100 | ||
EVAP vent control valve is damaged or stuck | Replace EVAP vent control valve | EVAP vent control valve: $150-$200 | ||
EVAP purge volume control valve is damaged or stuck | Replace EVAP purge volume control valve | Purge volume control valve: $150-$200 |
Mercedes-Benz S600 CEL – Causes, Diagnostic Codes, Potential Repairs, & Repair Costs
DTC Codes | Most Common Causes | Repair | Repair Cost | |
#1 | Spark plug is worn or broken | Replace spark plugs | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 | ||
#2 | Blown air injector fuse | Replace air injector fuse | Fuse: $10 | |
Faulty air pump | Replace air pump | Air Pump: $570-$710 | ||
Faulty air pump relay | Replace air pump relay | Air Pump Relay: $50-$75 | ||
#3 | Spark plug #3 is worn or broken | Replace spark plug #3 | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 | ||
#4 | Spark plug #2 is worn or broken | Replace spark plug #2 | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 | ||
#5 | Spark plug #1 is worn or broken | Replace spark plug #1 | Spark plugs: $66-$250 | |
Ignition coils are broken | Replace ignition coils | Ignition Coils: $230-$640 (some cars require Intake manifold removal) | ||
Spark plug wires are worn | Replace spark plug wires | Spark plug wires: $180-$240 | ||
Fuel injectors are broken | Replace fuel injectors | Fuel injectors: $1500-$1900 |
Mercedes-Benz SL500 CEL – Causes, Diagnostic Codes, Potential Repairs, & Repair Costs
DTC Codes | Most Common Causes | Repair | Repair Cost | |
#1 | Blown air injector fuse | Replace air injector fuse | Fuse: $10 | |
Faulty air pump | Replace air pump | Air Pump: $570-$710 | ||
Faulty air pump relay | Replace air pump relay | Air Pump Relay: $50-$75 | ||
#2 | Missing, loose, or damaged gas cap | TIghten or replace gas cap | Missing or damaged gas cap: $0-$20 | |
Leak in EVAP line | Fix leap in EVAP line | EVAP line: $20-$100 | ||
EVAP vent control valve is damaged or stuck | Replace EVAP vent control valve | EVAP vent control valve: $150-$200 | ||
EVAP purge volume control valve is damaged or stuck | Replace EVAP purge volume control valve | Purge volume control valve: $150-$200 |
Mercedes-Benz SLK230 CEL – Causes, Diagnostic Codes, Potential Repairs, & Repair Costs
DTC Codes | Most Common Causes | Repair | Repair Cost | |
#1 | Blown air injector fuse | Replace air injector fuse | Fuse: $10 | |
Faulty air pump | Replace air pump | Air Pump: $570-$710 | ||
Faulty air pump relay | Replace air pump relay | Air Pump Relay: $50-$75 | ||
#2 | Engine air filter is very dirty | Replace the engine air filter | Air filter $50-70 | |
Mass airflow sensor is dirty or broken | Replace the mass airflow sensor | Mass air flow sensor $220-320 | ||
Catalytic converter is damaged or worn | Replace the catalytic converter | Catalytic converter $1720-1780 | ||
#3 | Faulty engine coolant thermostat | Replace engine coolant thermostat | Replace engine coolant thermostat: $40 – $190 | |
#4 | Missing, loose, or damaged gas cap | TIghten or replace gas cap | Missing or damaged gas cap: $0-$20 | |
Leak in EVAP line | Fix leap in EVAP line | EVAP line: $20-$100 | ||
EVAP vent control valve is damaged or stuck | Replace EVAP vent control valve | EVAP vent control valve: $150-$200 | ||
EVAP purge volume control valve is damaged or stuck | Replace EVAP purge volume control valve | Purge volume control valve: $150-$200 |
Mercedes-Benz Sprinter 2500 CEL – Causes, Diagnostic Codes, Potential Repairs, & Repair Costs
DTC Codes | Most Common Causes | Repair | Repair Cost | |
#1 | P0299 | Faulty turbo or supercharger | Replace turbo or supercharger | Turbo or supercharger: $300 – $3400 |
Faulty boost pressure sensor | Replace boost pressure sensor | Boost pressure sensor: $200 – $220 | ||
#2 | P2463 | Faulty Diesel Particulate Filter | Replace Diesel Particulate Filter | Diesel Particulate Filter Replacement: $2500 – $8000 |
Clean Diesel Particulate Filter | Cleaning Diesel Particulate Filter: $150 – $200 |
FAQs – Mercedes-Benz Check Engine Light
How long can you drive with the check engine light?
Depending on how serious your Check Engine Light is, you may not want to drive. According to FIXD’s data on Check Engine Light causes, 40% of all Check Engine Lights are serious. Before you continue driving, pull over and figure out why it’s on.
If you have a Flashing Check Engine Light, the issue is likely serious. Misfires, a common cause of a flashing light, can cause severe and expensive engine damage. Unburnt fuel can make it into your exhaust and destroy your catalytic converter, which can cost over $1000 to replace. If your light is flashing, you probably want to get a tow, it will be cheaper in the long run.
If you have a Solid Check Engine Light or one that goes on and off seemingly at random or only under certain conditions (like hard acceleration), you may not need to get a tow and can probably drive a few days without a problem. But, you should pull over to check for common problems just to make sure the light is not an early warning sign of a larger issue like your car overheating, leaking fluids, or not pumping coolant or oil. Just get to a safe spot and check for the most common cause first: A loose gas cap. If that’s all it is, tighten it up and be on your way, the light should reset itself. If not, check out: What to Do When Your Check Engine Light Comes on. Checking for symptoms like rough idling, loud exhaust, or other warning lights will help you rule out a more serious problem.
Is it safe to drive your Mercedes-Benz with the check engine light on?
It’s usually safe to drive your car for a few days with your Check Engine Light on as long as it’s not flashing. Some problems like engine misfires, which generally cause your Check Engine Light to flash, can make your car harder to control and can even start a fire in your car if left untreated for long enough.
Although most times it’s safe to drive with your Check Engine Light on, you should always find out why it’s on ASAP. If something is seriously wrong with your car, the longer you drive, the higher the risk of costly repairs. According to FIXD’s data on Check Engine Light causes, 40% of all Check Engine Lights are serious.
What Does the Check Engine Light Mean?
When your Check Engine Light is on it means your car has identified a problem with the engine or transmission. There are over 1000 problems that can trigger a check engine light. Some are minor like a loose gas cap. Some, like an engine misfire, are more serious and can cause engine failure and/or damage.
The only way to know for sure what’s causing the check engine light is to diagnose it yourself or have a mechanic diagnose it. If you’d like to save some money; learning how to scan your car’s computer with a code reader isn’t hard and doing so will show you what system in your car is broken and you can narrow it down to likely repairs from there. This can help you decide if you can fix it or at the very least keep you from being overcharged at the mechanic. You can buy a small scanner like FIXD that fits in a glovebox, pocket, or purse if you want a clear answer on the severity of your light before you start driving again. Or check out: Where To Get Your CEL Checked if you need to find somewhere to get it checked fast.
What Does the Check Engine Light Look Like?
The check engine light is typically a yellow, orange, or red light in the shape of an engine on your car’s dashboard. Depending on the car, it might include the words “Check” or “Service Engine” inside or next to the engine symbol. The light might be solid or flashing depending on the cause of the check engine light.
At FIXD, our mission is to make car ownership as simple, easy, and affordable as possible. Our research team utilizes the latest automotive data and insights to create tools and resources that help drivers get peace of mind and save money over the life of their car.
