P1629

DTC P1629 Theft Deterrent Fuel Enable Circuit Incorrect Signal Detected During Cranking:

Theft Deterrent Fuel Enable Circuit:

CIRCUIT DESCRIPTION
The Vehicle Theft Deterrent module produces the Theft Deterrent Fuel Enable signal when ignition is "ON" and the proper key resistor pellet is sensed by the Vehicle Theft Deterrent module. The Powertrain Control Module (PCM) monitors the Fuel Enable signal during crank. If the proper signal is present on the Theft Deterrent Fuel Enable circuit, the PCM enables fuel delivery to allow the engine to start. If the PCM detects that the fuel enable signal is not present or incorrect while an attempt is made to start the engine, DTC P1629 will be set. The engine will not start as long as this condition is present. If the problem also affects inputs to the Vehicle Theft Deterrent module, the starter motor may be disabled. If this condition is present, refer to Antitheft and Alarm System for further diagnosis. Antitheft and Alarm Systems

CONDITIONS FOR SETTING THE DTC
- DTC P1626 not present.
- An attempt is made to start the engine.
- The PCM detects an incorrect signal on the Theft Deterrent Fuel Enable Circuit.
- The above conditions for longer than 2 seconds.

ACTION TAKEN WHEN THE DTC SETS
- The PCM will not illuminate the Malfunction Indicator Lamp (MIL).
- The PCM will store conditions which were present when the DTC set as Fail Records data only. This information will not be stored as Freeze Frame data.

CONDITIONS FOR CLEARING THE MIL/DTC
- A history DTC P1629 will clear after 40 consecutive warm-up cycles have occurred without a fault.
- DTC P1629 can be cleared by using the scan tool "Clear Info" function or by disconnecting the PCM battery feed.

DIAGNOSTIC AIDS
An intermittent may be caused by a poor connection, rubbed through wire insulation or a wire broken inside the insulation.
Check for:
- Poor connection. Inspect the PCM and Vehicle Theft Deterrent module harness and connectors for improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.
- Damaged harness. Inspect the wiring harness for damage. If the harness appears to be OK, disconnect the Vehicle Theft Deterrent module, turn the ignition "ON" and observe a voltmeter connected to the Theft Deterrent Fuel Enable circuit at the Vehicle Theft Deterrent module harness connector while moving connectors and wiring harnesses related to the Vehicle Theft Deterrent system. A change in voltage will indicate the location of the fault.

Reviewing the Fail Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.