TD21 - Check Harness and Connectors For Intermittent Faults

NOTE: This pinpoint test step is included to help isolate a possible intermittent Transmission Range switch circuit concern.

- Key "OFF".

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

- Install breakout box or 4EAT tester. Leave PCM disconnected

- Key "ON".

- Refer to the "4EAT Transmission Range Switch Voltage" chart.

Connect a test lamp between test pin 23 (TRR) and test pin 40 (GND). Observe test lamp for an indication of a fault while performing the following (the light will be normally on when the gear selector is in the same position as the circuit being tested (i.e., TRR=Reverse), and off in all other selector positions. A fault will be indicated by the light going off when it should be on (open in Transmission Range switch circuit or IGN Start/RUN circuit), or on when it should be off (short to power).

- Shake, wiggle, bend the Transmission Range switch circuit between the PCM and the transmission.

- Shake, wiggle, bend the IGN Start/RUN circuit.

- Lightly tap on the Inhibit Switch to simulate road shock.

- After completing testing on the TRR circuit, repeat the testing for the other Transmission Range Switch circuits (TRL, TRD, TROD).

- Key "OFF".

- Is a fault indicated?

Yes -- Isolate fault and service as necessary. Remove breakout box. Reconnect all components. Re-evaluate symptom.

No -- Return to Diagnosis by Symptom (Diagnostic Routines) to address this or any other symptom.