Automatic Transmission Gear Position Signal
- While observing gear indicator, shift transmission gear selector to each position. If gear indicator lights up correctly for all positions, go to next step.
- Turn ignition off. Disconnect 16-pin harness connector from gauge assembly. Disconnect 26-pin connector from Transmission Control Module (TCM). Turn ignition on. Measure voltage between PCM terminals B4 and A26. See Figure . If voltage is about 5 volts, go to step 4). If voltage is not as specified, go to next step.
- Turn ignition off. Disconnect PCM connector "B". Check for continuity between ground and PCM harness connector terminal B4. If continuity exists, repair shorted Yellow/Green wire between PCM terminal B4 and gauge assembly connector. If continuity does not exist, substitute a known-good PCM and retest.
- Turn ignition off. Reconnect wire harness to TCM and gauge assembly. Start engine. Measure voltage between PCM terminals B4 and A26 with transmission in Neutral. If voltage is less than one volt, go to next step. If voltage is one volt or greater, repair open Yellow/Green wire between PCM terminal B4 and gauge assembly or repair open Red wire between gauge assembly and gear position switch.
- Measure voltage between PCM terminals B4 and A26 with transmission in Park. If voltage is less than one volt, A/T gear position signal is functioning properly. If voltage is one volt or greater, repair open Black/Blue wire between gauge assembly and A/T gear position switch.