P0037

Diagnostic Chart:

Schematic:

The rear oxygen sensors are equipped with heater to asist in ramping up and maintaining a minimal operating temperature. The ECM diagnoses the heater and its related wiring by continuously monitoring electrical current. The ECM will set this DTC when the signal being received is lower than expected.

DTC PARAMETERS
This DTC will set when:
^ Engine speed greater than 40 rpm
^ Battery voltage is between 7.5 and 15 volts

DTC P0037 is a (type B) DTC

DIAGNOSTIC AIDS
To locate an intermittent problem use Scan tool to monitor HO2S heater circuit low voltage bank 1 sensor 2 voltage with engine idling at normal temperature.

Wiggling wires while monitoring HO2S Heater Bn 1 Sen. 2 voltage may locate area where a short to ground may exist.

Review failure record information to check if vehicle was running lean in power enrichment (TP angle greater than 75%, HO2S Bank 1 Sensor 2 reading greater than 1.2) when DTC was set. If so, check for a possible lean condition.