Code 1: Pump Motor Overrun

Bleed high-pressure fluid from maintenance bleeder using ABS "T" wrench. See RELIEVING SYSTEM PRESSURE under BLEEDING BRAKE SYSTEM. Remove pump motor relay. See Figure . Connect jumper wires between terminals No. 3 and 8. See Fig 1 through Fig 3 .

Fig 1: Identifying Underhood ABS Fuse/Relay Box
Courtesy of AMERICAN HONDA MOTOR CO.,

Fig 2: Identifying Pressure Switch Connector Terminals
Courtesy of AMERICAN HONDA MOTOR CO.,

Fig 3: Underhood ABS Fuse/Relay Box Circuit Diagram
Courtesy of AMERICAN HONDA MOTOR CO.,
If pump motor runs with a constant soft sound, bleed air from ABS using ABS tester. See AIR BLEEDING under BLEEDING BRAKE SYSTEM. Recheck pump sound. If pump motor runs with an increasingly loud, raspy sound, check fluid level in accumulator by bleeding high pressure line using ABS "T" wrench. See Fig 4 .

Fig 4: Measuring Modulator Fluid Level
Courtesy of AMERICAN HONDA MOTOR CO., INC.
If 40-70 cc is measured, go to next step. If fluid measured is not 40-70 cc, connect jumper wire between terminals No. 3 and 8 for about 10 seconds. See Fig 1 through Fig 3 . Check for changes in fluid level. If fluid level does not change, relief valve in pump motor is defective. Replace pump assembly. If fluid level changes, solenoid is defective (leaking). Replace modulator.
Connect jumper wire between terminals No. 3 and 8 for about 10 seconds. See Fig 1 through Fig 3 . Disconnect pressure switch 2-pin connector. Check continuity between pressure switch terminals. If continuity does not exist, replace pressure switch is defective. Replace pump assembly. If continuity exists, vehicle is okay at this time.