XB178 - Check DCL In VCRM

- Key "OFF".

- Powertrain Control Module (PCM) connected.

- Variable Control Relay Module (VCRM) connected.

- Disconnect engine cooling fan.

- A/C "OFF", defroster "OFF".

- Perform Key On Engine Off (KOEO) Self-Test. Quick Test Appendix (Detailed Testing Instructions)

- Is KOEO Diagnostic Trouble Code (DTC) 582 present?

Yes -- Reconnect cooling fan. No problem is indicated at this time. The DATA (+) and DATA (-) circuits check OK, and Data Link Connector (DLC) is operational in the PCM and VCRM. Return to Diagnostic Routines to address any other symptoms.

No -- Allow time for engine to cool down (to verify that the cooling fan will not attempt to come on). After engine is cooled down, start engine, wait 10 seconds, then turn engine "OFF". Rerun KOEO Self-Test. Quick Test Appendix (Detailed Testing Instructions)

If KOEO DTC 582 is still not present, replace VCRM. Reconnect cooling fan. Start engine. A/C "ON", wait 15 seconds. A/C "OFF". Engine "OFF". Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)