Main Relay/Power Circuit Failure
- Remove ABS system fuse from Power Distribution Center (PDC). Remove ABS main relay from PDC, and inspect connector. Repair connector as necessary. With DRB-II in ohmmeter mode, probe fused battery feed Red/Dark Green wire (Red/Light Green wire on Grand Cherokee and Grand Wagoneer or Red/Dark Blue wire on Wrangler) at ABS main relay socket. If resistance is less than 5 ohms, repair Red/Dark Green wire (Red/Light Green wire on Grand Cherokee and Grand Wagoneer or Red/Dark Blue wire on Wrangler) for a short to ground. Perform VERIFICATION TEST VER-1A. If resistance is more than 5 ohms, go to next step.
- Remove ABS pump/motor relay from PDC, and inspect connector. Repair connector as necessary. Using an external ohmmeter, measure resistance of ABS pump/motor relay coil. See Fig 1 . If resistance is 35-65 ohms, go to next step. If resistance is not 35-65 ohms, replace ABS pump/motor relay. Perform VERIFICATION TEST VER-1A.
- Disconnect hydraulic control unit 10-pin connector. With DRB-II in ohmmeter mode, probe Gray/Yellow wire (Gray/Pink wire on Grand Cherokee and Grand Wagoneer) at ABS main relay socket terminal "B". If resistance is less than 5 ohms, repair Gray/Yellow wire (Gray/Pink wire on Grand Cherokee and Grand Wagoneer) for a short to ground. Perform VERIFICATION TEST VER-1A. If resistance is more than 5 ohms, go to next step.
- Reconnect all disconnected components. Install a new ABS fuse in PDC and cycle ignition off and on. Inspect ABS fuse in PDC. If fuse is okay (does not blow), perform TEST 13C. If fuse is not okay (blows), replace hydraulic control unit. Perform VERIFICATION TEST VER-1A.