Universal (All Makes) Vehicle (OBD-II)
Severity:Common Causes
- map[cause:Short to ground in the pump control signal wire]
- map[cause:Internal short in the leak detection pump motor]
- map[cause:Damaged wiring rubbing against a metal ground surface]
- map[cause:Corroded pump connector causing a low-resistance path to ground]
- map[cause:Failed ECM output for the pump circuit]
How to Fix It
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Inspect the pump wiring harness for any areas rubbing on the chassis.
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Disconnect the pump connector and check if the code clears — isolates the fault.
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Test the control wire for shorts to ground with the pump unplugged.
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Measure pump motor resistance — a very low reading confirms an internal short.
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Repair any shorted wiring, or replace the pump if it has an internal fault.
Frequently Asked Questions
Will P2401 fail a smog test?
Yes. Any active check engine light will fail an emissions inspection. Get this repaired before your test date.
How do I find a short to ground in the wiring?
Disconnect the pump, then use a multimeter set to resistance. Measure between the signal wire and a chassis ground. A reading near zero ohms means there's a short.
Is P2401 expensive to fix?
Usually not. Wiring repairs and a replacement pump are affordable. Total cost is typically $50–$200 depending on labor rates.