Brake System Pump Motor Circuit Failure
There's a problem with the brake system pump motor circuit.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The computer monitors the brake pump motor that helps build pressure for the braking system. If it sees an issue, it flags a fault, which often means the motor is either not turning on or the circuit has an open or short.
What the computer is actually seeing
The brake control module expects the pump motor to receive a steady voltage supply between 10-14 volts when activated. If it receives 0 volts or fluctuating values beyond that range when it's supposed to operate, it'll trigger code C1291.
What a healthy reading looks like
Circuit should show 10-14 volts when the pump is activated, and the pump should draw around 5-10 amps.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Check brake fluid level. If it's low, top it off and retest. If this resolves the issue, inspect for leaks.
- 22. Inspect the wiring harness for visible damage or corrosion in the connectors. Repair or replace as needed.
- 33. Use a multimeter to test voltage at the brake pump connector. Activate the brake system and confirm voltage is between 10-14 volts.
- 44. If no voltage is present, trace back to the brake control module looking for broken, corroded, or disconnected wires. Repair as necessary.
- 55. If voltage is present but the pump does not operate, test the resistance of the pump motor. It should typically be between 2-8 ohms. Replace the motor if out of range.
Common causes
- Faulty brake pump motor
- Open or shorted wiring in the pump circuit
- Bad connector at the pump
- Low brake fluid level causing pump issues
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's not recommended, as brake performance may be compromised if the pump is not functioning.
Will the code come back after clearing it?
Yes, if the underlying issue isn't fixed, the code will likely return.
Why does this code appear with other brake-related codes?
They often relate to the same brake system components and issues affecting overall brake performance.
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