2010 Cadillac CTS Sedan AWD V6-3.6L Page 1795
The remote control door lock receiver (RCDLR) sends the prerelease password to the engine control module (ECM) via the serial data circuit. The
ECM then sends a challenge to the RCDLR. Both the ECM and RCDLR perform a calculation on this challenge. If the calculated response from the
RCDLR 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 RCDLR 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 RCDLR is reliant on the communications between the transponder located in the vehicle key and
the RCDLR. Failure to establish communications or an interruption in the communications between the vehicle key and the RCDLR will cause the
fuel disable message to be sent and the setting of DTC B1632. DTC B3055 or B3060 will be set in the RCDLR. 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
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit
Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Wiring Repairs/Wiring Repairs)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
Circuit/System Verification
Important: Because of normal system communications between the RCDLR and ECM, any theft deterrent B-codes must be diagnosed
prior to the diagnosis of P-codes.
Perform the 10-Minute Immobilizer Relearn procedure. Refer to Immobilizer System Component Programming (without RPO Y41) (See:
Accessories and Optional Equipment/Antitheft and Alarm Systems/Testing and Inspection/Programming and Relearning/Immobilizer System
Component Programming (without RPO Y41))Immobilizer System Component Programming (with RPO Y41) (See: Accessories and Optional
Equipment/Antitheft and Alarm Systems/Testing and Inspection/Programming and Relearning/Immobilizer System Component Programming (with
RPO Y41)). The ECM should successfully complete the password learn and the vehicle should start.
If the ECM does not complete the learn or vehicle starting remains disabled, replace the ECM.
