2010 Cadillac CTS Sedan AWD V6-3.0L Page 1772
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
Control Module References (See: Testing and Inspection/Programming and Relearning) for ECM replacement, setup and programming
Without Y41
DTC P1632 (without Y41)
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides an overview of each diagnostic category.
DTC Descriptor
DTC P1632
- Theft Deterrent Fuel Disable Signal Received
Circuit/System Description
The theft deterrent module (TDM) sends the prerelease password to the engine control module (ECM) via the serial data circuit. The ECM then
sends a challenge to the TDM. Both the ECM and TDM perform a calculation on this challenge. If the calculated response from the TDM equals
the calculation performed by the ECM, the ECM will allow vehicle starting.
Conditions for Running the DTC
Ignition is in the RUN position.
Conditions for Setting the DTC
A fuel disable signal from the TDM is received by the ECM.
Action Taken When the DTC Sets
* The security indicator will illuminate.
* Vehicle starting will be disabled.
Conditions for Clearing the DTC
* A current DTC P1632 will be when a valid calculation is received.
* A history DTC will be cleared after 40 malfunction-free ignition cycles or when a scan tool is used to clear DTCs.
Diagnostic Aids
The prerelease password sent to the ECM by the TDM is reliant on the communications between the transponder located in the vehicle key and the
TDM. Failure to establish communications or an interruption in the communications between the vehicle key and the TDM will cause the fuel
disable message to be sent and the setting of DTC B1632. DTC B3055 or B3060 will be set in the TDM. To properly diagnose DTC P1632, DTC
B3055 or B3060 must be diagnosed and corrected first.
Reference Information
Schematic Reference
Immobilizer Schematics (See: Accessories and Optional Equipment/Antitheft and Alarm Systems/Diagrams/Electrical Diagrams/Immobilizer
Schematics)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Description and Operation
Immobilizer Description and Operation (without Y41) (See: Accessories and Optional Equipment/Antitheft and Alarm Systems/Description and
Operation/Immobilizer Description and Operation (Without Y41))Immobilizer Description and Operation (with Y41) (See: Accessories and
Optional Equipment/Antitheft and Alarm Systems/Description and Operation/Immobilizer Description and Operation (With Y41))
Electrical Information Reference
