P1626 On Chevrolet, GMC and Buick, the engine computer is not receiving the fuel-enable message from the theft-deterrent system

GM theft deterrent fuel enable signal lost or not received

Severity not verified — if the car runs badly, have it inspected

GM bulletins tie P1626 to no-start and hard-start, so the car may not start or may stall, but none of the sources rate the risk. An Equinox owner reports a limp-mode shudder with the code.

Source: how we rate severity

P1626 in short

On Chevrolet, GMC and Buick, P1626 means the engine computer did not get the "fuel enable" message from the theft-deterrent system. GM bulletins link it to no-start and hard-start. Owners report a flashing security light and, in some cases, a failed body control module or key relearn.

GM's theft-deterrent system must tell the engine computer that the key is valid before fuel is enabled. If the message is missing, the computer sets P1626 and may refuse to run the engine.

GM bulletins cover no-start with P1626 on trucks, utilities and vans from 1998 to 2004, and slow or extended cranking on the S series. Owners of a 2003 Impala and a 2006 Equinox report a flashing security light, hard starting and lost-communication codes.

Owner reports mention replacing the body control module and re-learning the keys, but one owner says neither always works, so treat both as things to test, not guaranteed repairs.

Pick your make

P1626 is a manufacturer-specific code: its meaning depends on who built the car.

Other makes: meaning not verified. Check with a scan tool that reads manufacturer definitions.

Most likely causes

  1. Body control module or theft-deterrent module not sending the enable message

    Supported by vehicle data
    Why it ranks here
    An Equinox owner reports the dealer replaced the body control module three times before the third cured it, and an Impala owner says the BCM is a common repair for this code but does not always fix it.
    What would change this
    Rises if the security light flashes and the key relearn fails. Falls if the key relearn restores the signal.
    How to test the body control module (bcm)

  2. Key or theft-deterrent learn data lost

    Possible — needs testing
    Why it ranks here
    The Impala owner tried a key relearn without success. Whether a relearn fixes P1626 on other cars is not stated by any source here.
    What would change this
    Rises if the problem began after battery, module or key work. Falls if the relearn fails.

  3. Voltage drop or lost communication between modules

    Possible — needs testing
    Why it ranks here
    An Avalanche owner saw P1626 with StabiliTrak disabled and several lights on, and read it as a loss of communication between modules, and the Equinox code list includes lost communication with the ECM and TCM.
    What would change this
    Rises if other lost-communication codes are stored. Falls if P1626 is the only code.

What to test first

Start at step 1. Each result tells you what it means and where to go next.

  1. Read all codes and note whether the security light flashes when you try to start. Check whether other lost-communication (U-) codes are stored.

    Low riskTool: scan tool

Symptoms

  • Engine will not start or cranks slowly with a flashing security light
  • Theft deterrent light and traction control light on together
  • Intermittent no-crank that clears on its own

How to fix

Parts and cost context

  • Body control module (BCM):Owner reports describe replacing the module, sometimes repeatedly. Prove the fault first. Labour and programming vary; get a quote.

Labor varies by vehicle and shop; get a quote before you approve a repair.

Compare used part prices on PartPriceGuide

On your vehicle

Chevrolet

  • 2002–2003 · Impala

    Supported by vehicle data

    Owners of a 2002 and a 2003 Impala report P1626 with hard starting or no-crank.

  • 2006 · Equinox

    Supported by vehicle data

    A 2006 Equinox owner reports P1626 with lost-communication codes and limp mode, fixed by the third replacement body control module.

  • 876521Status unverified

    Slow cranking, extended cranking and hard starting with P1626

    1998s-10-pickup · NHTSA 609646

    Summary names slow cranking, extended cranking time, P1626 and hard starting on the 1998 S series. Only the summary was read.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

No curated relationships for P1626 yet.

All Body electrical codes

Sources and review

  1. GM service bulletins naming DTC P1626 (theft deterrent, no start / hard start) — General Motors / NHTSA
  2. NHTSA complaint ODI 10176882: 2006 Chevrolet Equinox, P1626 — NHTSA Office of Defects Investigation (owner complaint)
  3. NHTSA complaint ODI 11255789: 2003 Chevrolet Impala, P1626 — NHTSA Office of Defects Investigation (owner complaint)
  4. NHTSA complaint ODI 10690995: 2005 Chevrolet Avalanche 1500, P1626 — NHTSA Office of Defects Investigation (owner complaint)
  5. NHTSA complaint ODI 10186385: 2002 Chevrolet Impala, P1626 — NHTSA Office of Defects Investigation (owner complaint)
  6. P1626 trouble code definition by make — troublecodes.net
Last reviewed
Written by
Saurabh K.
Editorial review
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Technician review
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