Powertrain
generic / SAE
P0037
HO2S Heater Control Circuit Low (Bank 1 Sensor 2)
O2 sensor heater control circuit on bank 1, sensor 2 reports low voltage. Likely shorted to ground or open in the heater control wire. The heater warms the sensor element to operating temperature (~600 °C); without it the sensor stays inactive in closed loop and the ECM cannot trim mixture.
SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number– / 37
Possible causes
- Heater wire shorted to ground high
- Connector pins corroded - high contact resistance low
- Harness chafing through insulation low
Inspection / repair
- Difficulty: easy
- DIY: possible
- Estimated cost: 80–350 €
- Estimated time: 0.5–1.5 h
- Component: oxygen sensor heater
- Component: sensor wiring
- MIL / check engine light
- emissions-relevant
- drive cycle required
Sources
References
sae:J2012