P1252
Fuel Pump Diagnostic Signal Incorrect
What it means
P1252. Fuel Pump Diagnostic Signal Incorrect. This Chevy-enhanced code applies to Silverado, Sierra, Tahoe, Yukon, Suburban.
Findings, check these first
- Failing fuel pump control module reporting an incorrect diagnostic signal
- Chafed or corroded wiring between the fuel pump control module and the ECM
- Poor ground at the fuel pump control module raising feedback voltage
- Aftermarket remote-start or alarm taps spliced into the fuel pump circuit
Standard procedure
- Check fuel pump operation and pressure with a gauge before electrical testing
- Inspect the fuel pump control module connector for corrosion and terminal tension
- Test the diagnostic signal wire end to end for opens, shorts, and excess resistance
- Remove any aftermarket splices in the fuel pump harness and restore wiring
- Replace the fuel pump control module only after wiring tests pass
Look up another code
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Sources and review
Review: no source links are recorded for this entry.
Last updated 2026-09-19.
Report a correction for P1252. Include your vehicle, the issue and a source if you have one.
This fault is part of the Chevy P1xxx fuel and ignition codes guide. It covers the family and the order to check it.