Test D: Incorrect Speedometer Reading: ZX2
- Turn ignition switch to LOCK position. Connect scan tool and retrieve Diagnostic Trouble Codes (DTC) following manufacturer's instructions. If no DTCs are present, go to next step. If DTCs are present, repair DTCs as necessary. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. Retest system operation.
- Using scan tool, observe Vehicle Speed Sensor (VSS) output Parameter Identification (PID) while assistant drives vehicle over range of speeds on various road surfaces. If VSS PID varies smoothly with vehicle speed, go to next step. If VSS PID does not vary or is erratic, repair VSS concern. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. Retest system operation.
- Remove and check OBD-II fuse (10-amp) in Battery Junction Box (BJB). BJB is located in engine compartment, next to battery. See Figure. If fuse is blown, go to next step. If fuse is not blown, reinstall fuse and go to step 5.
- Turn ignition switch to LOCK position. Remove instrument cluster. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. Disconnect instrument cluster harness connectors. Measure resistance between ground and White instrument cluster 12-pin harness connector C258 terminal No. 1 (Green wire). See Figure. If resistance is more than 10 k/ohms, replace OBD-II fuse (10-amp) and go to next step. If resistance is less than 10 k/ohms, repair short to ground in Green wire. See WIRING DIAGRAMS . Retest system operation.
- Turn ignition switch to LOCK position. Remove instrument cluster, if not already removed. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. Disconnect instrument cluster harness connectors. Measure voltage between ground and White instrument cluster 12-pin harness connector C258 terminal No. 1 (Green wire). See Figure. If voltage is more than 10 volts, go to next step. If voltage is less than 10 volts, repair open in Green wire. See WIRING DIAGRAMS . Retest system operation
- Turn ignition switch to LOCK position. Disconnect Vehicle Speed Sensor (VSS) 2-pin harness connector C132. Measure resistance of Blue wire between VSS 2-pin harness connector C132 terminal No. 2 and Black instrument cluster 12-pin harness connector C252 terminal No. 11. See Figure. Measure resistance of White/Black wire between VSS 2-pin harness connector C132 terminal No. 1 and Black instrument cluster 12-pin harness connector C252 terminal No. 1. Resistance in both tests should be less than 5 ohms. If resistances are as specified, go to next step. If resistances are not as specified, repair open in White/Black and/or Blue wire. See WIRING DIAGRAMS . Retest system operation
- Measure resistance between ground and Black instrument cluster 12-pin harness connector C252 terminal No. 1 (White/Black wire). If resistance is more than 10 k/ohms, go to next step. If resistance is less than 10 k/ohms, repair short to ground in White/Black wire. See WIRING DIAGRAMS . Retest system operation.
- Turn ignition switch to ON position. Measure voltage between ground and White instrument cluster 12-pin harness connector C258 terminal No. 12 (Black/Yellow wire). See Figure. If voltage is more than 10 volts, go to next step. If voltage is less than 10 volts, repair open in Black/Yellow wire. See WIRING DIAGRAMS . Retest system operation
- Turn ignition switch to LOCK position. Visually inspect instrument cluster printed circuit for damage, cracks or hot spots. If instrument cluster printed circuit appears okay, replace speedometer. See FUEL GAUGE, TEMPERATURE GAUGE, SPEEDOMETER/ODOMETER & TACHOMETER INDICATORS/WARNING BULBS under REMOVAL & INSTALLATION. Retest system operation. If instrument cluster printed circuit appears damaged, replace printed circuit and gauge contact clips. See PRINTED CIRCUIT under REMOVAL & INSTALLATION. Retest system operation.