What does P1626 mean on a Chevy?

P1626. Theft Deterrent Fuel Enable Signal Not Received. Applies to Silverado, Sierra, Tahoe, Impala, Malibu, Cavalier.

What causes P1626 on a Chevy?

Failing Passlock sensor in the ignition lock cylinder housing Broken Class 2 serial data wire between the BCM and PCM Weak battery voltage during cranking corrupting the BCM-to-PCM password exchange Aftermarket remote starter interfering with the Passlock signal

How do I fix P1626 on a Chevy?

Watch the theft deterrent status and fuel-enable password on a Tech2/GDS2 scan tool during cranking Load-test the battery first; low cranking voltage is a common false trigger Inspect for aftermarket remote start or alarm splices into the Passlock wiring Perform the 30-minute Passlock relearn procedure after any lock cylinder or BCM replacement

Code

P1626

Theft Deterrent Fuel Enable Signal Not Received

Category: Powertrain - Computer and Auxiliary Controls
Severity: Check Engine Light
Applies to: Silverado, Sierra, Tahoe, Impala, Malibu, Cavalier
Related: No single generic twin. See OBD Codes List

What it means

P1626. Theft Deterrent Fuel Enable Signal Not Received. This Chevy-enhanced code applies to Silverado, Sierra, Tahoe, Impala, Malibu, Cavalier.

Findings, check these first

Failing Passlock sensor in the ignition lock cylinder housing
Broken Class 2 serial data wire between the BCM and PCM
Weak battery voltage during cranking corrupting the BCM-to-PCM password exchange
Aftermarket remote starter interfering with the Passlock signal

Standard procedure

Watch the theft deterrent status and fuel-enable password on a Tech2/GDS2 scan tool during cranking
Load-test the battery first; low cranking voltage is a common false trigger
Inspect for aftermarket remote start or alarm splices into the Passlock wiring
Perform the 30-minute Passlock relearn procedure after any lock cylinder or BCM replacement

Look up another code

Press / to jump to the box. Chevy-enhanced powertrain, body, chassis and network codes.

Sources and review

Review: no source links are recorded for this entry.

Last updated 2026-09-13.

Report a correction for P1626. Include your vehicle, the issue and a source if you have one.

This fault sits in the GM theft deterrent system. The GM security codes and Passlock relearn guide covers the families and the relearn cycles.