P0141

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 also monitors the internal resistance of the sensor. The measured value is compared to a reference internal resistance that is computed using the heater and exhaust gas temperature. If the internal resistance is too high, this DTC will set.

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

DTC P0141 is a (type B) DTC

DIAGNOSTIC AIDS
To locate an intermittent problem use Scan tool monitor HO2S Heater Bn 1 Sen. 2 voltage with engine idling at normal temperature.

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