P0037
Low SeverityHO2S Heater Control Circuit Low (Bank 1, Sensor 2)
Emissions System
What Does P0037 Mean?
Low voltage in the downstream O2 sensor heater on bank 1. The heater element has likely burned out.
Common Fix
Replace downstream O2 sensor
Estimated Cost (DIY)
$25 - $80
Symptoms
- ⚠️Check engine light
- ⚠️Failed emissions
- ⚠️No performance symptoms
- ⚠️Possible false cat efficiency code
Related Symptoms
Common Causes
How to Diagnose P0037
- 1Check heater fuse
- 2Measure heater resistance (should be 2-30 ohms)
- 3Inspect wiring
- 4Replace sensor if heater is open
OEM Diagnostic Flowchart
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Related Resources
Repair guides, symptom pages, and wiring diagrams related to P0037.
OEM Manual Evidence
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A L L Diagnostic Trouble Codes ( DTC ) — 2013 GMC Truck Acadia AWD V6-3.6L Service Manual | Operation CHARM Operation CHARM : Car repair ma...
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Related Symptoms
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Exact Repair Workflows
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Open the exact repair flow most commonly associated with P0037 on this vehicle.
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Open the exact repair flow most commonly associated with P0037 on this vehicle.
Related Codes
The heater circuit for the downstream (post-cat) O2 sensor on bank 1 has failed. This sensor monitors catalytic converter efficiency.
The heater in the downstream O2 sensor on bank 1 has failed.
The O2 sensor heater circuit voltage is lower than expected on the upstream bank 1 sensor. Usually means an open circuit in the heater element.
Frequently Asked Questions
- What is the difference between P0036 and P0037?
- P0036 is a general heater circuit fault; P0037 specifically means the voltage is low (open circuit). Both usually need a sensor replacement.
- How long can I drive with P0037?
- Indefinitely — there are no driveability effects. However, it will cause emissions test failure.
Related Repair Guides
If your vehicle has triggered P0037, these DIY repair guides may help: