P2534

DTC P2534

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.

DTC Descriptor
DTC P2534
- Ignition 1 Switch Circuit Low Voltage

Circuit/System Description

The transmission control module (TCM) samples the system voltage on the Ignition 1 voltage circuit every 0.1 seconds. Lower than normal voltage may be inadequate to operate the transmission control solenoids properly. Improper solenoid operation may cause erratic transmission operation, which may result in internal damage.

Conditions for Running the DTC

The engine is running.

Conditions for Setting the DTC

The TCM detects an open or short to ground on the Ignition 1 voltage circuit.

Action Taken When the DTC Sets

* DTC P2534 is a Type A DTC.
* The TCM commands maximum line pressure.
* The TCM freezes transmission adaptive functions.
* The TCM turns off power to all solenoids.
* The transmission will operate in fifth gear if the vehicle has successfully completed a 1-2 upshift in the current ignition cycle. If the vehicle has not completed a 1-2 upshift in the current ignition cycle, the transmission will operate in fourth gear.
* The TCM inhibits Powertrain Braking.
* The TCM inhibits Autograde Braking.
* The TCC is disabled.
* The TCM inhibits Torque management.

Conditions for Clearing the DTC

DTC P2534 is a Type A DTC.

Diagnostic Aids

* If all circuit tests are OK, ensure the transmission pass through connector and harness terminals are clean and not damaged, and the charging system is functioning correctly.
* Verify there is a good connection at the body control module (BCM) especially if DTC P0700 is also set with this code.

Reference Information
Schematic Reference

Automatic Transmission Controls Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Transmission General Description (Transmission General Description)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
Scan Tool Reference

Transmission Control Module Scan Tool Information (Transmission Control Module Scan Tool Information)

Circuit/System Testing

Test the ignition 1 voltage circuit of the TCM for an open or short to ground.

Refer to Control Module References (Programming and Relearning) for replacement, setup, and programming.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the repair.

Control Module References (Programming and Relearning) for TCM replacement, setup, and programming