Bleed high-pressure fluid from maintenance bleeder using ABS "T" Wrench (07HAA-SG00100). See RELIEVING ACCUMULATOR/LINE PRESSURE under BLEEDING BRAKE SYSTEM. Disconnect pump motor relay connector, and remove relay. See Figure . Connect terminals No. 1 and 2 together for about 8 seconds using a jumper wire. See Fig 1 .

Fig 1: Identifying Pump Motor Relay Connector Terminals (Legend)
Courtesy of AMERICAN HONDA MOTOR CO., INC.
If pump motor runs with a constant soft sound, use ABS "T" wrench to bleed air from brake system at maintenance bleeder and recheck pump sound. If pump motor runs with an increasingly loud, raspy sound, bleed high pressure fluid from maintenance bleeder using bleeder "T" wrench. Check modulator reservoir fluid level. See Fig 2 .
If 40-70 cc of fluid exists in reservoir, go to next step. If 40-70 cc of fluid does not exist in reservoir, use a jumper wire to connect terminals No. 1 and 2 of pump motor relay together for about 10 seconds. See Fig 1 . Check fluid reservoir level. If fluid level does not change, relief valve in pump motor is defective. If fluid level changes, solenoid is defective (leaking).
Using a jumper wire, connect terminals No. 1 and 2 together for about 10 seconds. See Fig 1 . Disconnect pressure switch 2-pin connector. Check for continuity between pressure switch terminals. If no continuity exists, replace defective pressure switch. If continuity exists, accumulator is defective.

Fig 2: Measuring Modulator Reservoir Fluid Level (Legend & Vigor)

Courtesy of AMERICAN HONDA MOTOR CO., INC.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Code 1, Pump Motor Overrun