DTC 28: TCS Relay
- Inspect TCS fuse (20-amp) located in underhood fuse/relay block. If fuse is blown, replace fuse and retest system. If fuse is okay, go to next step.
- Turn ignition on. Recheck TCS fuse. If fuse is blown, repair short circuit in Red/Blue wire between TCS relay and modulator unit. See Figure. If fuse is okay, go to next step.
- Check TCS relay operation. See RELAYS under COMPONENT TESTS. Replace as necessary. If TCS relay is okay, leave relay unplugged and go to next step.
- Using DVOM, measure voltage between TCS relay plug-in terminal No. 1 and ground. See Figure. If battery voltage is present, go to next step. If battery voltage is not present, repair open circuit in Blue wire between TCS relay and TCS fuse (20-amp). See WIRING DIAGRAMS .
- Using fused jumper wire, connect TCS relay plug-in terminals No. 1 (Blue wire) and 2 (Red/Blue wire) together. Disconnect modulator unit. Using DVOM, measure voltage between modulator unit harness connector terminal No. 17 (Red/Blue wire) and ground. If battery voltage is present, go to next step. If battery voltage is not present, repair open circuit in Red/Blue wire between modulator unit harness connector terminal No. 17 and TCS relay plug-in terminal No. 2.
- Remove fused jumper wire from TCS relay plug-in terminal. Using DVOM, measure voltage between modulator unit harness connector terminal No. 17 (Red/Blue wire) and ground. If battery voltage is present, repair short to voltage in Red/Blue wire between modulator unit harness connector terminal No. 17 and TCS relay plug-in terminal No. 2. See WIRING DIAGRAMS . If battery voltage is not present, go to next step.
- Disconnect ABS/TCS control unit 16-pin connector "B". Using DVOM, measure voltage between ground and ABS/TCS control unit 16-pin connector "B" terminal No. 13 (Green/Yellow wire). If battery voltage is present, repair short to voltage in Green/Yellow wire between ABS/TCS control unit harness connector "B" terminal No. 13 and TCS relay plug-in terminal No. 3. If battery voltage is not present, go to next step.
- Using DVOM, check for continuity between ground and ABS/TCS control unit 16-pin connector "B" terminal No. 13 (Green/Yellow wire). If continuity is indicated, repair short circuit to ground in Green/Yellow wire between ABS/TCS control unit 16-pin connector "B" terminal No. 13 and TCS relay plug-in terminal No. 3. See WIRING DIAGRAMS . If continuity is not indicated, go to next step.
- Turn ignition off. Remove fail-safe relay from ABS/TCS relay block. Using fused jumper wire, connect fail-safe relay plug-in connector terminals No. 1 (White/Green wire) and 2 (Brown/Black wire) together. See Figure. Using DVOM, measure voltage between TCS relay plug-in terminal No. 4 (Brown/Black wire) and ground. If battery voltage is present, go to next step. If battery voltage is not present, repair open circuit in Brown/black wire between TCS relay plug-in terminal No. 4 and fail-safe relay plug-in connector terminal No. 2. See WIRING DIAGRAMS .NOTE: Be sure to leave ABS/TCS control unit 16-pin connector "B" unplugged for following step.
- Using fused jumper wire, connect TCS relay plug-in connector terminals No. 4 (Brown/Black wire) and 3 (Green/Yellow wire) together. See Figure. Using DVOM, measure voltage between ABS/TCS control unit 16-pin connector "B" terminal No. 13 (Green/Yellow wire) and ground. If battery voltage is not present, repair open circuit in Green/Yellow wire between ABS/TCS control unit 16-pin connector "B" terminal No. 13 and TCS relay plug-in terminal No. 3. If battery voltage is present, if problem reoccurs, replace ABS/TCS control unit.