Testing Procedure

NOTE: For ME-SFI control module location and identification, see ME-SFI CONTROL MODULE CONNECTOR IDENTIFICATION .

O2 Signal - Connect DVOM between left cylinder bank ME-SFI control module connector 1 terminals No. 40 and 42 (socket box terminals No. 40 and 42). Start engine and idle. Keep engine speed between 2000-3000 RPM for approximately 2 minutes after engine coolant temperature reaches more than 176°F (80°C). Allow engine to idle. Voltage must exceed or drop to less than 450-500 millivolts within one minute. If voltage is okay, test is complete. If voltage is not okay, possible causes are left O2 sensor (after TWC) heater failure, wiring harness failure, defective left O2 sensor (after TWC - G3/5) or defective left cylinder bank ME-SFI control module (N3/11). To check left O2 sensor (after TWC) heater failure, go to DTC P0161: O2 SENSOR HEATING OF LEFT O2 SENSOR DOWNSTREAM TWC (G3/5) .