What Does Code P0068 Mean?
- P0068 definition: MAP/MAF – Throttle Position Correlation
- Issue Severity: SEVERE – Stop driving immediately
- Repair Urgency: Fix this code immediately (same day if possible) to avoid engine and catalytic converter damage.
- Diagnosis: This trouble code can cause some pretty severe driveability concerns and may make the vehicle undrivable. It can also affect how efficiently the engine runs and cause damage to the catalytic converter(s).
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The ECM relies on the input from the mass airflow (MAF) sensor to determine how much air is being ingested into the engine, the throttle position sensor (TPS) to determine how much the throttle body is being opened, and the manifold absolute pressure (MAP) sensor to determine what the pressure is inside the intake manifold. When this code is set, the ECM is seeing voltages from these sensors that don’t make sense in relation to each other and determines that there is a fault.
There are many potential causes of code P0068.
- Vacuum leak
- Dirty air filter
- Intake air leak
- Clogged or disconnected line to MAP sensor
- Carbon buildup on the throttle body
- Faulty mass airflow sensor
- Dirty mass airflow sensor
- Faulty manifold absolute pressure sensor
- A faulty throttle position sensor
- Poor electrical connections at sensors
- Check Engine Light
- Hard/No Start
- Rough Idle
- Hesitation On Acceleration
- Lack Of Power
- No noticeable adverse conditions in some cases
How Do I Fix Code P0068?
With a sensor fault, the first step is to get it diagnosed to figure out what is causing the problem.
If your vehicle has this fault and you’re not comfortable diagnosing this issue at home, we recommend finding a RepairPal certified shop nearby to pinpoint the problem and give an accurate estimate for repairs.
These shops can not only help you figure out what’s going wrong before you waste time and money on the wrong parts, but they also offer a minimum 12-month, 12,000-mile warranty and stand behind all their estimates with guaranteed fair pricing.
How Much Does It Cost to Fix Code P0068?
P0068 can be caused by anything from a bad sensor to a vacuum leak to a dirty air filter. It’s impossible to give an accurate estimate without properly diagnosing the issue first.
If you take your car to a shop for diagnosis, most shops will start with an hour of “diag time” (the time spent in labor diagnosing your specific issue). Depending on the shop’s labor rate, this typically costs somewhere between $75-$150. Many, if not most, shops will apply this diagnosis fee to any required repairs if you have them perform the repairs for you. From there, a shop will be able to give you an accurate estimate for repairs to fix your P0068 code.
Possible Repair Costs for P0068
For error code P0068, one or more of the below repairs may be needed to solve the underlying issue. For each possible repair, the estimated cost of repair includes the cost of the relevant parts and the cost of labor required to make the repair.
- Fix intake/vacuum leak: $150-$250
- Wiring repair/replacement: $100-$1000
- Air filter: $20
- Replace throttle position sensor: $170-$230
- Throttle body cleaning: $230-$290
- Replace manifold absolute pressure sensor: $150-$200
- Clean mass airflow sensor: $100
- Replace mass airflow sensor: $300
DIY Steps to Diagnose Code P0068
Engine code P0068 could be caused by a number of things, including a faulty sensor, a vacuum leak, or even a dirty air filter. If you’d like to try to fix code P0068 at home without throwing money at parts, you’ll want to follow the steps below for proper diagnosis. Keep in mind that this is an intermediate-level diagnosis and repair and is not recommended for beginners. Diagnosis requires more specialized equipment beyond what the FIXD Sensor can provide and it can be a time and labor-intensive process for inexperienced DIYers.
DIY difficulty level: Intermediate
This repair requires mechanical knowledge and is not recommended for beginners.
Tools/parts needed (our top picks from Amazon):
- Basic hand tools
- Mass airflow cleaner
- Throttle body cleaner
STEP 1: USE FIXD TO ENSURE NO OTHER ENGINE CODES ARE PRESENT.
Check to see if there are any other codes along with P0068 with FIXD. If there are any other MAF, MAP, or TPS-related codes, diagnose them first before diagnosing code P0068.
STEP 2: CHECK AIR FILTER.
Check the condition of the air filter and replace it if it’s dirty.
STEP 3: CHECK WIRING.
Conduct a visual inspection of wiring and connectors at the MAP, MAF, and TPS for fraying, disconnection, or poor pin fitment.
STEP 4: CHECK FOR VACUUM LEAKS.
Conduct a visual and audible inspection of the vacuum lines and any intake connections to make sure there are no signs of disconnection or outside air leaks. This includes the intake pipe between the throttle body and MAF. Listen for a hissing sound which can be a sign of a vacuum leak.
Spray water over the intake area and listen for the engine RPM to drop or stumble. If it goes down, there is an intake leak. Concentrate the stream on different hoses and gaskets until you find your leak.
STEP 5: CHECK AND CLEAN MASS AIR FLOW SENSOR.
Check the Mass Air Flow sensor to make sure that it’s not dirty and possibly sending false readings which affect the O2 sensor. If it is dirty, clean it, clear your codes using the FIXD device, and re-scan to see if the code is still triggered.
STEP 6: CHECK AND CLEAN THROTTLE BODY.
Remove the intake pipe from the throttle body and inspect the throttle body for carbon build-up. If it is dirty, clean it, clear the codes using the FIXD device, and re-scan to see if the code is still triggered. DO NOT spray the throttle body with the cleaner. Spray it on a rag and wipe the butterfly surfaces and housing clean.
STEP 7: CHECK MAP SENSOR.
If the manifold absolute pressure sensor is mounted remotely from the intake manifold, verify that air passes through the vacuum line feeding it.
STEP 8: TEST THROTTLE POSITION SENSOR.
Using a multimeter, back probe the TPS connector while plugged in, the ignition on, and the engine off. One wire should have battery voltage, around 12 volts. One wire will have less than 0.1 volts. The other wire should have 0.5 or so volts with the throttle closed and a little less than 5 volts with the throttle wide open. The voltage should also steadily increase as you slowly open the throttle. If it jumps or dips, replace the throttle position sensor.
STEP 9: TEST MASS AIR FLOW SENSOR.
Back probe the MAF sensor connector while plugged in, the ignition on, and the engine off. One wire should have battery voltage, around 12 volts. One wire will have less than 0.1 volts. One wire is for the intake temp sensor, if so equipped (this will not be tested for this code). The last wire will be our signal wire. Start the engine and monitor this voltage. It should change with engine RPM. If it doesn’t, replace the mass air flow sensor.
STEP 10: TEST MANIFOLD ABSOLUTE PRESSURE SENSOR.
Back probe the MAP sensor connector while plugged in, the ignition on, and the engine off. One wire should have battery voltage, around 12 volts. One wire will have less than 0.1 volts. The other wire should have 4.5 to 5 volts. Start the engine, and this voltage should drop to between .5 and 1.5 volts depending on your altitude and the air temperature. Gently press the gas pedal to raise the engine RPM. The voltage should react to the throttle opening by dropping and rising again. If not, replace it.
Common P0068 diagnosis mistakes
The most common diagnosis mistake is the replacement of sensors without inspecting for any vacuum or intake leaks.
Still Need Help Fixing Code P0068?
If you’ve followed the steps above and are still experiencing check engine code P0068, please contact the FIXD Mechanic Hotline if you’re a FIXD Premium subscriber or find a RepairPal certified shop near you to get the right repairs at a fair price.
Recovering autocross and track day enthusiast. Once turned a VW Jetta into a pickup truck. Lives in a van down by the river. Dream car: 2001 Subaru WRC rally car.