Test Description

Numbers below refer to step number on Diagnostic Chart:

1. 1. The Malfunction Indicator Lamp (MIL) should be ON steady with ignition ON and engine OFF. If not, go to "Diagnostic Aids".
2. 2. Checks Class 2 data circuit and ensures that PCM/ECM is able to transmit serial data.
3. 3. This test ensures PCM/ECM is capable of controlling MIL and that MIL driver circuit is not shorted to ground.
4. 4. If engine will not start, refer to "Engine Cranks But Will Not Run".
5. 7. A scan tool parameter which is not within typical range may help to isolate area which is causing problem.
6. 10. This vehicle is equipped with a PCM/ECM which utilizes an electrically erasable programmable read only memory (EEPROM). The replacement PCM/ECM must be programmed.

Fig 1: OBD II Circuit Wiring Diagram

Courtesy of DAEWOO

Fig 2: On-Board Diagnostic (OBD II) System Check

Courtesy of DAEWOO