Diagnostic Procedures
WARNING: This page is about a different car, the 2002 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
If DTC P0050, P0051 or P0052 is also set, diagnose that DTC first. See DTC P0050: HO2S HEATER CIRCUIT - BANK 2, SENSOR 1
, DTC P0051: HO2S HEATER CIRCUIT - LOW VOLTAGE - BANK 2, SENSOR 1
or DTC P0052: HO2S HEATER CIRCUIT - HIGH VOLTAGE - BANK 2, SENSOR 1
.
- Run engine above 1500 RPM for one minute. Ensure ECT is more than 158°F (70°C). Let engine idle. Using scan tool, monitor HO2S bank 2 sensor 1. If reading is varying outside 400-538 mV, problem intermittent. See DIAGNOSTIC AIDS . If reading is not varying outside 400-538 mV, go to next step.
- Turn ignition on, engine off. Disconnect HO2S bank 2 sensor 1. Connect jumper between HO2S connector terminal No. 4 (Purple wire) and ground. If reading is less than 40 mV, go to next step. If reading is not less than 40 mV, check Purple wire between HO2S and ECM for open. If wire is okay, replace ECM.
- Connect jumper between HO2S connector terminals No. 3 (Tan wire) and No. 4 (Purple wire). If reading is not less than 40 mV, check Tan wire between HO2S and ECM for open. If wire is okay, replace ECM. Check HO2S connector. If connector is okay, replace HO2S bank 2 sensor 1.