DTC 53: Modulator Unit Pump Motor Stuck On
- If modulator unit pump motor runs with ignition off, replace ABS pump motor relay in underhood ABS/TCS relay block. See Figure. If ABS pump motor does not run with ignition off, go to next step.
- Remove and inspect ABS MOTOR CHECK fuse (7.5-amp) in passenger's underdash fuse/relay block. If fuse is blown, replace fuse and retest system. If fuse is not blown, leave ABS MOTOR CHECK fuse out and go to next step.
- Turn ignition on. Using DVOM, measure voltage between ground and passenger's underdash fuse/relay block 16-pin connector "J" terminal No. 5 (Green wire). See Fig 1. If voltage reading is 10 volts or more, go to next step. If voltage is less than 10 volts, repair open circuit in Green wire between passenger's underdash fuse/relay block 16-pin connector "J" terminal No. 5 and ABS/TCS control unit 26-pin connector "A" terminal No. 20. See WIRING DIAGRAMS .
- Reinstall ABS MOTOR CHECK fuse (7.5 amp). Disconnect modulator unit 24-pin connector. Measure voltage between ground and modulator unit 24-pin connector terminal No. 1 (White/Blue wire). If voltage reading is 10 volts or more, go to next step. If voltage is less than 10 volts, repair open circuit in White/Blue wire between modulator unit 24-pin connector terminal No. 1 and underhood fuse/relay block.
- Measure voltage between modulator unit 24-pin connector terminals No. 1 (White/Blue wire) and 16 (Black wire). If voltage reading is 10 volts or more, go to next step. If voltage is less than 10 volts, repair open circuit in Black wire between modulator unit 24-pin connector terminal No. 16 and ground. See WIRING DIAGRAMS .
- Remove pump motor relay from ABS/TCS relay block. Using fused jumper wire, connect pump motor relay plug-in terminals No. 4 and 5 together. See Figure. If pump motor runs, go to next step. If pump motor does not run, replace pump motor.
- Disconnect ABS/TCS control unit 16-pin connector "B". Using DVOM, check for continuity between ground and ABS/TCS control unit 16-pin connector "B" terminal No. 15 (Yellow/Red wire). If continuity is indicated, repair short circuit to ground in Yellow/Red wire between ABS/TCS control unit 16-pin connector "B" terminal No. 15 and ABS/TCS relay block. If continuity is not indicated, retest system. If problem reoccurs, replace ABS/TCS control unit.
Courtesy of AMERICAN HONDA MOTOR CO., INC.