Test D: Fail-Safe Relay
NOTE:
Fail-safe relay is an integral component of ABS relay.
- Check System Integrity
Visually check wiring, connectors, brakelines and components for damage, looseness or short circuits. If faults are found, repair as necessary. If no faults are found, go to next step. - Fuse Check
Check 60-amp ABS PUMP fuse, located in main fuse block. Also check 15-amp ENGINE fuse, located in interior fuse block. If fuses are blown, check for short to ground in wiring between fuse block and ABS relay. Repair wiring as necessary. If fuses are okay, go to next step. - Check Relay Operation
Turn ignition off. Disconnect ABS control module. ABS control module is located behind left cowl side trim panel. Turn ignition on. Connect a jumper wire between ground and Black/Blue wire at ABS control module connector. If relay clicks, go to next step. If relay does not click, inspect Black/Blue wire from relay to ABS control module. If fault is found, repair wire. If no fault is found, go to step 6) - ABS Warning Light Diode Check
Ensure jumper wire is still connected between ground and Black/Blue wire at ABS control module connector. Turn ignition on. Observe ABS warning. Light should be off when Black/Blue wire is grounded. If ABS warning light turns on, go to step 6). If ABS warning light stays off, go to next step. - Check Voltage From ABS Relay
Ensure ABS control unit is disconnected and jumper wire is still connected. Turn ignition on. Set DVOM on 20-volt scale. Measure voltage between ground and Yellow/White wire at ABS control module connector. If voltage is 10 volts or less, go to next step. If voltage is more than 10 volts and technician was directed to this test from TEST F, go to TEST E . If technician was not directed here from TEST F and voltage is more than 10 volts, go to TEST G . - Check ABS Relay
Turn ignition off. Disconnect ABS relay. Using DVOM, measure resistance between ABS relay terminals indicated. See ABS RELAY RESISTANCE table. See Fig 1 . Replace relay if resistance is not as specified.
ABS RELAY RESISTANCE
| Terminals | Ohms |
|---|---|
| "D" and "E" | 60-100 |
| "B" and "C" | More Than 10,000 |
| "B" and "F" | Less Than 5 |
| "F" and "J" | Less Than 50-90 |
| "B" and "J" | Less Than 50-90 |
| "C" and "G" | More Than 10,000 |
If relay resistance is okay, perform the following:
- Apply 12 volts to ABS relay terminal "E" and ground to terminal "D". Set DVOM on 20-k/ohm scale. Measure resistance between ABS relay terminals "B" and "F". See Fig 1 . Resistance should be more than 10,000 ohms.
- Set DVOM on 200-ohm scale. Measure resistance between ABS relay terminals "C" and "F". See Fig 1 . Resistance should be less than 5 ohms.
- Apply 12 volts to ABS relay terminal "H" and ground to terminal "J". Set DVOM on 200-ohm scale. Measure resistance between ABS relay terminals "C" and "G". See Fig 1 . Resistance should be less than 5 ohms. Remove 12 volts and ground from relay terminals.
- Set DVOM to diode check mode. Connect DVOM negative lead to terminal "F" and positive lead to terminal "H". See Fig 1 . Continuity should be present. Connect DVOM positive lead to terminal "F" and negative lead to terminal "H". Continuity should not be present. If ABS relay fails any test, replace relay.