P2634: Fuel Pump B Control Circuit High
What to do
The symptom is the one described at P2632 — trouble when the tank gets low, cured by filling up.
If anything has been done to the fuel tank, the fuel pump, the fuel gauge sender or the rear of the car recently, mention it first. The connector for this pump is reached through an access panel under the back seat or boot floor, or by dropping the tank, so it is disturbed by all of that work and is easy to leave unmated or trapped. Checking it is cheap; replacing a pump because of it is not.
What this code means
The second fuel pump's control circuit reads above its valid range — an open circuit, a disconnected connector, or a short to supply. The mechanism is at P2632.
The connector for an in-tank pump is reached by removing the tank or lifting an access panel under a rear seat or boot floor, which means it is disturbed by any work in that area — a pump replacement, a level sender, a fuel leak repair, or bodywork after a rear-end impact. A code appearing straight after any of those is an unmated or trapped connector until shown otherwise, and that is a very different job from a new pump.
Where the vehicle has no access panel and the tank must come out to reach it, that distinction is worth several hours.
Likely causes
Start here
- Open circuit in control wiring · moderate
- Disconnected sensor connector · easy
- Corroded or loose connector · easy
Less common
- Faulty fuel transfer pump · moderate
- Wiring shorted to voltage · moderate
Symptoms
Components involved
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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