No Serial Data

Diagnostic Chart:

Circuit Description

There should always be a steady Malfunction Indicator Lamp (MIL) when the ignition is ON and the engine is stopped. Battery voltage supplies the lamp. The VCM turns the lamp on by grounding the MIL control circuit whenever a DTC sets and the DTC meets the requirements for illuminating the MIL.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

2. This step checks the battery feed circuit to the Data Link Connector (DLC).

3. This step checks the DLC grounds.