Air & Fuel Mixture ControlOBD2 Codes

P0037 – Meaning, Causes, Symptoms, & Fixes

Reading Time: 2 minutes


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

    1. (A.S.A.P. assistance needed)I got this code on one of those inexpensive scanners from harbor freight,Im experiencing a loud engine as well as severely lowered acceleration power , i push 75% down to full throttle on the gas and go very slow, engine roaring quite loudly,i drive over 100 miles daily quite often, i do have a history of over running the mileage (such as the past six months)for changing my oil filter as well as more than a few times driving long distances with nearly empty oil level, in the past few months ive noticed the engine making a slight subtle noise like growling when accelerating and dimming a bit once going highway speeds, but ignored it putting off inspection, now here i am ,unable to drive to work any assistance on the matter would be greatly appreciated A.S.A.P.

      1. You’re kidding right. Nobody, not even a rookie could make so many bad judgment calls. Driving with almost no oil…. Come on now. If you knew enough to check the oil level, then you knew enough not to drive it when it was that low. No offense if this is really what happens but it sure seems like you’re yanking some chains and it’s probably stick to riding a bicycle. But no offense. I’d just be scared to drive near you for fear that your engine may explode at any time… But, at least I wouldn’t have to worry about any hot oil getting on me, just a part of an engine block through my chest or something.

    2. I have this error in my car but I earing some knocking too. Someone know if this caused for this error ?

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

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

  4. Thanks for this posting…

  5. thanks a lot for this info.

  6. will cruse control light come on

  7. What fuse is associated with the O2 sensor?

    1. It comes on whenever check engine light comes on… and of course disables the cruse control too

  8. I had my catalyst converter stolen off of my car and they also removed a few feet of exhaust pipe from my car with it. This has to be why this code is coming up on my car right?

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