XB177 - Verify DCL In VCRM

- Key "OFF".

- Powertrain Control Module (PCM) connected.

- Variable Control Relay Module (VCRM) connected.

- A/C "OFF".

- Enter Output State Diagnostic Test Mode (OS DTM).

- Outputs "OFF".

- Depress throttle (near Wide Open Throttle (WOT)), wait until the Malfunction Indicator Light (MIL) flashes once (about 10 seconds). Release throttle.

- Cooling fan should come on.

- Depress throttle to turn fan "OFF".

- Does fan come on and turn off as requested during Output State check?

NOTE: The cooling fan can only be cycled once while in OS DTM. To retest, exit and re-enter OS DTM.

Yes -- Exit OS DTM. Go to XB178. XB178 - Check DCL In VCRM

No -- Verify OS DTM is operating properly. (The MIL can be viewed and should change when the throttle is depressed and released. If the MIL does not change, check throttle linkage, Data Link Connector (DLC) connections, etc.) If OS DTM is operating properly, replace VCRM. Reconnect all components. Start engine. A/C on, wait 15 seconds. A/C "OFF". Engine "OFF". Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)