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XB181 - Check Data (+)/Data (-) Circuits: Intermittent Shorts



- Key "OFF".

- Disconnect test equipment from Data Link Connector (DLC).

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

- 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 jumper wire between the DATA (+) (automatic transmissions/O) and DATA (-) (PK/LB) circuits at the DLC.

- Connect a test lamp between test pin 19 and test pin 37 at the breakout box.

- Observe test lamp for an indication of a fault while performing the following, (the test lamp will come on when a fault is detected, indicating a short to ground):

- Shake, wiggle, bend the DATA (+) and DATA (-) circuits between the PCM and VCRM connectors and between the DLC and splice.

- Reconnect test lamp between test pin 19 and test pin 40 at the breakout box.

- Key "ON".

- Observe test lamp for an indication of a fault (test lamp will come on, indicating a short to power) while exercising the DATA (+) and DATA (-) circuits as done above.

- Key "OFF".

- Remove jumper wire.

- Is a fault indicated?

Yes -- Isolate fault and service as necessary. Remove breakout box. Reconnect all components. Start engine. Turn A/C "ON", wait 15 seconds. A/C "OFF". Engine "OFF". Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)

No -- Go to XB182. XB182 - Check Data (+)/Data (-) Circuits: Intermittent Opens