Circuit Description
When the ignition is switched On, the antenna that is integrated in the Theft Deterrent Module (Immobilizer) is energized. During this period the Engine Control Module (ECM) sends a signal to terminal 2 of the Theft Deterrent Module requesting the frequency code (imo signal).
The transponder key contains a security code (transponder code) that transmits via the antenna to the Theft Deterrent Module. The Theft Deterrent Module compares the received code with the stored transponder code. If the transponder code is recognized, the Theft Deterrent Module blocks the speed signal input to the ECM allowing the transfer of the imo signal to terminal 44 of the ECM. The ECM compares the received imo signal with the programmed imo signal. If the signal is recognized and matches the programmed signal the engine is allowed to start.
Within 1.5 seconds during the transfer and the evaluation phase of the transponder code and the imo signal the engine can be started. However, if the imo signal does not match, the engine will stall immediately.
Conditions for Setting the DTC
| • | No transponder signal (key transmitter signal) present, transponder key defective. |
| • | Key used is not a transponder key. |
| • | Transponder key not programmed in the Theft Deterrent Module. |
The above conditions must be fulfilled for at least 0.51 seconds.
Action Taken When the DTC Sets
| • | The engine starts then stalls. |
| • | The Theft Deterrent Module stores a DTC 12 in memory. |
Conditions for Clearing the DTC
| • | The conditions for the fault are no longer present. |
| • | A history DTC will clear after 20 consecutive ignition cycles if the condition for the fault is no longer present. |
| • | The use of a scan tool. |
Diagnostic Aids
Refer to Inducing Intermittent Fault Conditions in Wiring Systems.
Test Description
The following numbers refer to the step numbers on the diagnostic table:
-
This step checks which transponder key is being used.
-
This step checks the programmed status of the key being used.
-
The module may be at fault if no trouble is found in with the connection at the Theft Deterrent Module.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: Diagnostic System Check - Theft Deterrent | ||||
1 | Did you perform the Theft Deterrent Diagnostic System Check? | -- | ||
Does the scan tool display a transponder key (TRANSP KEY 1-5)? | -- | |||
3 | Does the scan tool display NOT PROGR KEY? | -- | ||
Select TRANSPONDER KEY STATUS. Does the scan tool display KEYS PROGRAMMED? | -- | Go to Diagnostic Aids | ||
5 |
Is the repair or replacement complete? | -- | -- | |
6 | Does the scan tool display NO KEY PROGR? ( Key being used is not programmed in the Theft Deterrent Module.) | -- | -- | |
7 | Program the transponder key. Refer to Programming Transponder Key. Was the programming successful? | -- | ||
8 |
Does the vehicle start? | -- | System OK | |
9 | Inspect for poor connections at the harness connector of the theft deterrent controller (VTD) module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
10 |
Does the DTC reset? | -- | ||
Did you complete the replacement? | -- | -- | ||
12 |
Important: All keys must be re-learned by the VTD module if the module is being replaced or a key has been replaced. Refer to Replacing Keys . Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | |
