P1626 on Pontiac: How to Diagnose & Fix
Theft Deterrent Fuel Enable Signal Lost
1 Pontiac model · 1 documented issue · 1 critical · $250-$550 repair
P1626 on Pontiac by model: symptoms, diagnosis and fix
The Passlock theft-deterrent sensor built into the ignition lock cylinder wears and sends an unstable resistance signal to the body control module, which then interprets a legitimate key as a theft attempt. The system disables the fuel injectors, leaving the car cranking but not starting with the SECURITY light flashing, and the failure typically recurs and worsens until owners are stranded repeatedly. This is one of the most widely documented complaints on the 1999-2005 Grand Am, with a 23+ page Edmunds thread and a RepairPal-confirmed pattern failure.
Common Symptoms
- Engine cranks but won't start
- SECURITY light flashing or stuck on
- Car starts after waiting 10 minutes with key on
- Intermittent no-starts that become more frequent
- Stalling shortly after start-up with security light on
How to Fix
Replace the ignition lock cylinder (which contains the Passlock sensor) and perform the 10-30 minute Passlock relearn procedure. As a stopgap, owners can do the 10-minute relearn (key on, wait for the security light to stop flashing) to start the car; many DIYers permanently bypass the sensor with an inline resistor on the Passlock signal wires.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- ACDelco 19258699 ignition-lock housing with Passlock sensor
Housing/sensor is distinct from the keyed lock cylinder; perform the exact relearn and confirm connector/VIN.
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Sources for this issue (5)
- 2003 Pontiac Grand Am Passlock Problem, Won't Start And Security Light Is Blinking: 25 Complaintsarticle
- Security light on Pontiac Grand Am — Car Talk Community (2004 Grand Am, Passlock ignition switch failure)forum
- Pontiac Grand Am Security Passlock Problems — Edmunds Car Forums (23+ pages)forum
- No Start Due to Failed Passlock Sensor: Pontiac Grand Am Electrical System — RepairPalarticle
- NHTSA complaints, 2002 Pontiac Grand Am — multiple ODI records for Passlock/security-light no-start (10898347, 10622496, 10503032, 10726457)nhtsa
P1626 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P1626 mean on a Pontiac?
P1626 stands for "Theft Deterrent Fuel Enable Signal Lost." This is a manufacturer-specific (commonly GM) anti-theft code indicating that the fuel-enable signal from the theft-deterrent system was lost or not received by the engine control module. As a security measure, the immobilizer or body control module must send a valid signal authorizing the ECM to deliver fuel; without it, the ECM disables fueling so a stolen vehicle cannot be driven. The result is usually an engine that cranks but will not start, often with a security light on. It generally points to a security-system communication or authentication problem rather than a fuel or engine mechanical fault. On Pontiac it is documented across 1 model: Grand Am.
What are the most common causes of P1626?
The most common causes of P1626 are: Communication fault between the body control module and ECM, Faulty or unrecognized key/transponder or immobilizer issue, Damaged wiring or connectors in the theft-deterrent circuit, Faulty body control module (BCM), Faulty or improperly programmed engine control module, Loss of power or ground to a security-system module, Modules not properly relearned after a battery or part replacement. The specific cause varies by vehicle.
How much does it cost to fix P1626 on a Pontiac?
Published repair estimates on Pontiac range from $250 to $550 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P1626 on a different make?
View P1626 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.