Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Code A031: Pump Motor Feedback Circuit Open
When pump motor relay contacts are open, the pump on input is grounded through pump motor relay and pump motor. When the pump motor relay contacts are closed, the pump on input and pump motor will have voltage applied. If the pump on Input does not sense these conditions, the anti-lock brake controller will set Code A031.
- If Code A036 is set, check for bad connection at pump motor relay or connector C160.
- If Code A035 is set, inspect for open pump motor circuit.
- Determines if pump motor feedback circuit is open.
- If pump motor remains on, inspect for open in the pump motor circuit preventing pump motor from activating.
- Determines if open exists in circuit No. 150 between pump motor and ground G106.
- Battery voltage indicates malfunction at anti-lock brake controller and/or connector.
- Tests pump motor circuit to isolate defective pump motor.
- If resistance between terminals "E" and "F" of the pump motor relay is infinite, open exists inside pump motor relay.
NO RELATED
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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.