DTC 1-4: Pressure Switch

Relieve system pressure. See RELIEVING ACCUMULATOR/LINE PRESSURE under BLEEDING BRAKE SYSTEM. Disconnect ABS modulator unit 14-pin connector. Using DVOM, check for continuity between ABS modulator unit 14-pin connector terminals No. 4 (Yellow wire) and No. 11 (Black wire). See Figure . If continuity does not exist, go to next step. If continuity exists, visually check ABS modulator unit harness. If harness is okay, replace ABS modulator unit, as pressure switch is stuck on.
Disconnect ABS control unit 26-pin connector. Using DVOM, check for continuity between ground and ABS control unit 26-pin connector terminal No. 19 (Yellow wire). See Figure . If continuity exists, repair short to ground in Yellow wire between ABS control unit and ABS modulator unit. See WIRING DIAGRAMS . If continuity does not exist, check for poor connection to ABS control unit. If connection is okay, replace ABS control unit.