Two different permissions
The theft-deterrent module enables the starter crank circuit and also sends a separate fuel-enable signal to the PCM.
LT1 · 1996 · VATS
1996 LT1 VATS Fuel-Enable / P1626
A car can crank and still be denied injector operation. Separate starter authorization from PCM fuel enable.
APPLICATION: 1996 Firebird / Formula / Trans Am 5.7L VIN P LT1 with factory theft-deterrent strategy.
Cranking does not prove VATS is satisfied
If the proper fuel-enable signal does not reach the PCM, the PCM can withhold injector pulses even if the engine is cranking.
P1626 direction
DTC P1626 is set when the engine is cranking/running and the PCM does not receive the expected theft-deterrent fuel-enable signal.
Symptom-first branch
- Confirm cranking behavior and observe the SECURITY indicator/state.
- Check whether spark and injector pulse are present during the actual no-start.
- If spark/reference activity exists but injector pulse is withheld, include VATS/fuel enable in the branch before fuel-system parts.
- Inspect factory and aftermarket security/remote-start wiring before condemning a PCM or theft module.
- After repair, verify both start authorization and injector operation through repeated key cycles.
FPV RULE
OBSERVE → MEASURE → ISOLATE → PROVE → REPAIR → VERIFY. Do not turn a symptom, DTC or catalog fitment label into a parts order.