P0037 – Meaning, Causes, Symptoms, & Fixes

Code P0037 Definition

H02S2 Heater Control Circuit Low (Bank 1, Sensor 2)

What Does P0037 Mean?

The HO2S2 (heated oxygen sensor 2) sensor calculates the air to fuel ratio of the vehicle’s exhaust. The P0037 code is set when the ECM detects that the HO2S2 on bank 1 has a malfunctioning heater element. The heater in the oxygen sensor helps get the sensor up to operating temperature faster in order to improve fuel economy and emissions. This O2 sensor is located after the catalytic converter and monitors the catalytic converter’s efficiency.

What Are the Symptoms of Code P0037?

  • Check Engine Light
  • Poor Emissions
  • Poor Engine Performance
  • Lower Fuel Economy

What Causes the Code P0037?

  • Faulty Bank 1 Oxygen Sensor 2 Heater (Most likely cause)
  • Malfunctioning ECM Sensor Heater Driver
  • Shorted Control Circuit
  • A break in the wire between ECM and HO2S2
  • Poor Ground
  • Blown Fuse

What Is the Severity of Code P0037?-Low


This trouble code will not prevent your vehicle from operating, but it will cause it to fail emissions tests. The most common error(s) include lowered fuel economy, rough engine performance, and HO2S2 sensor errors. It is recommended to have this code fixed to prevent further damage to the vehicle.

Common Diagnosis Mistakes of Code P0037

Prematurely replacing the HO2S2 (heated oxygen) sensor without visually inspecting the wiring of the control circuit for disconnection or damage.

Tools Needed to Diagnose Code P0037

How to Diagnose Code P0037

Difficulty of Diagnosis: 2 out of 5

  1. Check to see if there are any other codes along with P0037 and clear your Check Engine Light with FIXD.
  2. Visually inspect the wiring around the bank 1 HO2S2 for disconnection or damage.
  3. If the wiring directly attached to the HO2S sensor is damaged, replace the HO2S2.
  4. Check resistance of the heater element to ensure it is within the specified range. If out of spec, replace HO2S2.
  5. Check voltage to the O2 heater. If no voltage is detected (open circuit), check for a blown fuse or break in the wire.
  6. Check ground to the heater, if no or poor ground, check for loose ground, clean, and tighten.
  7. If the problem persists, consider replacing the HO2S sensor, before replacing the ECM. 

Estimated Cost of Repair

For error code P0037, 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.

  • Heated oxygen sensor: $200-$300
  • Wiring repair/replacement: $100-$1000
  • ECM: $1000-$1200

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Comments 4


April 2, 2019

Turns out it was a blown fuse… after we changed the O2 sensor


June 10, 2019

Will this problem cause the vsc trac off light to come on?


July 10, 2019

Found loose connection ; passenger side , under carpet, left side, where the O2 sensor enters the cabin


October 16, 2019

Thanks for this posting…

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