DTC 31: Engine Retard Command Signal
NOTE:
If MIL indicator is on, go to SELF-DIAGNOSTIC SYSTEM
in SELF-DIAGNOSTICS - 3.2CL article in ENGINE PERFORMANCE. If ABS indicator is on, retrieve ABS DTCs and go to ABS DIAGNOSTIC TESTS .
- Disconnect 20-pin PCM connector "E" and ABS/TCS control unit 16-pin connector "B". Using DVOM, check for continuity on Blue wire between ground and PCM harness connector "E" terminal No. 7. See Fig 1. If continuity is indicated, repair short circuit to ground on Blue wire between PCM harness connector "E" terminal No. 7 and ABS/TCS control unit 16-pin connector "B" terminal No. 10. See Figure. See WIRING DIAGRAMS . If continuity is not indicated, go to next step.NOTE: Use an analog voltmeter set to 10-volt scale for following steps.
- Reconnect 20-pin PCM connector "E". Start engine. Measure voltage between ground and 20-pin PCM connector "E" terminal No. 7. If voltage reading is about 2.5 volts, go to next step. If voltage is not as specified, check for poor connections at PCM. If connections are okay, substitute known-good PCM and retest system.
- Measure voltage between ground and ABS/TCS control unit 16-pin connector "B" terminal No. 10. If voltage reading is about 2.5 volts, check for poor connections at ABS/TCS control unit. If connections are okay, substitute known-good ABS/TCS control unit and retest system. If voltage reading is not as specified, repair open circuit in Blue wire between PCM harness connector "E" terminal No. 7 and ABS/TCS control unit 16-pin connector "B" terminal No. 10.