X131 - Check For Intermittent Open Between EATC Module and PCM

- Key "OFF".

- Disconnect Powertrain Control Module (PCM). Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.

- Install breakout box, leave PCM disconnected.

- Connect a non-powered test lamp between test pin 10 and test pin 40 at the breakout box.

- Key "ON".

- A/C "ON".

Pressure Switch Circuit:

- Observe test lamp for an indication of a fault while performing the following (the light will turn off when a fault is detected, indicating an open):

- Shake, wiggle, bend the AC Demand (ACD) / AC Clutch Supply (ACCS) circuit between the Electronic Automatic Temperature Control (EATC) module and PCM. The drawing above shows the portion of circuit to be checked.

- Lightly tap the cyclic pressure switch to simulate road shock.

- Disconnect and inspect the cyclic pressure switch connector and the EATC module connector.

- Is a fault indicated?

Yes -- Isolate fault and service as necessary. Remove breakout box. Reconnect all components. Clear continuous memory. Clearing Diagnostic Trouble Codes

Start engine and Turn A/C on for about 2 minutes. Engine "OFF", A/C "OFF". Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)

No -- Unable to duplicate fault at this time. Remove breakout box. Reconnect all components. Clear continuous memory. Clearing Diagnostic Trouble Codes

Return to Diagnostic Routines to service any additional symptoms. Symptom Related Diagnostic Procedures