Refer to
Fuel Pump Relay and the Theft Deterrent System
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 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 Vehicle Theft Deterrent System for further diagnosis.
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 Failure Records data only. This information will not be stored as Freeze Frame data. |
Conditions for Clearing the MIL/DTC
| • | A History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction. |
| • | The DTC can be cleared by using the scan tool Clear Info function. |
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 monitor 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.
Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table.
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This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | Go to Powertrain OBD System Check | |
2 |
Important: Before continuing diagnosis, ensure that the vehicle battery is fully charged. Attempt to start vehicle. Does engine crank? | -- | Refer to Theft Deterrent System in Electrical Diagnosis | |
3 |
Does voltage measure near the specified value? | 5V | ||
4 |
Is the frequency between the specified values? | 40-60 Hertz | ||
5 |
Does the vehicle start and continue running? | -- | Refer to Diagnostic Aids | |
6 |
Was a problem found? | -- | ||
7 |
Was a problem found? | -- | ||
8 |
Was a problem found? | -- | ||
Replace the PCM. Important: Replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming Is action complete? | -- | -- | ||
10 | Replace the Theft Deterrent module. Is action complete? | -- | -- | |
11 |
Does VTD Fuel Disable display Inactive? | -- | Repair complete |
