XB180 - Check Data (+)/Data (-) Circuits: Intermittent Concerns

WARNING: While performing this test step, the engine cooling fan may turn on. Keep clear of the engine cooling fan.

- Start engine.

- A/C "OFF".

- Engine cooling fan "OFF". (This test is to be performed while the cooling fan is off.)

- Check for cooling fan coming on (for other than normal operation) while performing the following, (the Variable Control Relay Module (VCRM) will turn the fan on if a Data Link Connector (DLC) communication fault is detected): Shake, wiggle, bend the DATA (+) and DATA (-) circuits between the Powertrain Control Module (PCM) and VCRM, and between the DCL and splice.

- Lightly tap on the VCRM to simulate road shock.

- Did the cooling fan come on for other than normal operation?

Yes -- Isolate fault and service as necessary. Clear continuous memory. Clearing Diagnostic Trouble Codes

Start engine. Turn A/C "ON", wait 15 seconds. A/C "OFF". Engine "OFF". Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)

No -- Key "OFF". Go to XB181. XB181 - Check Data (+)/Data (-) Circuits: Intermittent Shorts