Code 1, Pump Motor Overrun
- Start engine and allow to idle for one minute. Check pump motor and ANTI-LOCK light operation. If pump motor runs for 40 seconds then light comes on, go to next step. If pump motor and light do not operate as described, vehicle is okay at this time.
- Check fluid level in modulator reservoir. See Fig 1
. If fluid level is not okay, replace modulator. If fluid level is okay, stop engine and go to next step.
- Disconnect modulator 14-pin connector. Check continuity between Yellow wire and Black wire terminals of 14-pin connector. If continuity exists, go to next step. If continuity is not present, replace modulator unit.
- Measure voltage between Yellow wire terminal of 14-pin connector and ground. If battery voltage is not present, go to next step. If battery voltage exists, check pressure switch ground connection. If ground connection is okay, repair open Black wire between pressure switch and ground.
- Measure voltage between Yellow wire terminal of control unit 26-pin connector and ground. If battery voltage exists, repair open Yellow wire between pressure switch and control unit. If battery voltage is not present, check control unit connectors. If connectors are okay, install known-good control unit and retest.
Courtesy of AMERICAN HONDA MOTOR CO., INC.