Note. Bank No. 1 refers to bank which includes cylinder No. 1. Bank No. 2 refers to bank without cylinder No. 1. Heated oxygen sensor No. 1 refers to sensor closest to engine block. Heated oxygen sensor No. 2 refers to sensor furthest away from engine block.
Circuit Description
The oxygen sensor monitors exhaust gas oxygen content and delivers an input signal to ECM. ECM uses this input signal to determine fuel injection system operation. Sensors include heater.
DTC P0136 is for bank No. 1, sensor No. 2. DTC P0156 is for bank No. 2, sensor No. 2. DTC is set when sensor voltage remains at .4 volt or more or .5 volt or less during vehicle operation at 19 MPH or more, once engine is at normal operating temperature. Possible causes are
- Open or short in heated oxygen sensor circuit.
- Faulty heated oxygen sensor.
Diagnostic Aids
Using scan tool, read freeze frame data. Freeze frame records engine conditions when malfunction is detected.