Test Description

Number(s) below refer to step number(s) on Diagnostic Table.

1. 1. The On-Board Diagnostic (OBD II) System Check prompts technician to complete some basic checks and store freeze frame and failure records data on scan tool if applicable. This creates an electronic copy of data taken when malfunction occurred. The information is then stored on scan tool for later reference.
2. 2. The engine must be allowed to cool fully before ECT and Idle Air Temperature (IAT) sensors will read close to ambient temperature in order to check for a possible skewed sensor.
3. 3. Measure engine coolant temperature with a thermometer to determine actual value ECT sensor should be. Take into consideration if engine has been run and engine coolant has been warmed without opening thermostat.
4. 5. This step simulates a DTC P0117. If PCM/ECM senses change, PCM/ECM and wiring are okay.
5. 6. The ECT sensor, PCM/ECM and wiring have checked okay at this point. Check for a proper thermostat and cooling fan operation.
6. 10. The replacement PCM/ECM must be programmed.

Fig 1: DTC P0125: Engine Coolant Temperature Insufficient For Closed Loop Operation (1 Of 2)

Courtesy of DAEWOO

Fig 2: DTC P0125: Engine Coolant Temperature Insufficient For Closed Loop Operation (2 Of 2)

Courtesy of DAEWOO