Note. Bank No. 1 refers to bank that includes cylinder No. 1. Bank No. 2 refers to bank without cylinder No. 1. Sensor No. 1 refers to sensor closest to engine block. Sensor No. 2 refers to sensor furthest away from engine block.
| CAUTION | If ECM replacement is instructed in following testing, always ensure ECM harness connector and ground circuit are okay. If either are suspect, repair and repeat testing to confirm ECM malfunction. |
Circuit Description
The oxygen sensor monitors exhaust gas oxygen content and delivers an input signal to ECM. The ECM uses this input signal to determine fuel injection system operation. Sensors include heater. DTC P0135, P0141 and P0155 are set when oxygen sensor heater circuit draw is more than 2 amps, or .25 or less amps of current. Possible causes are
- Heated Oxygen Sensor Open Or Short Circuit
- Heated Oxygen Sensor Heater
- ECM