P2534

DTC P2534

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provide an overview of each diagnostic category.



DTC Descriptors
DTC P2534
- Ignition 1 Switch Circuit Low Voltage




Diagnostic Fault Information






Typical Scan Tool Data






Circuit/System Description

The transmission control module (TCM) samples the system voltage on the ignition 1 voltage circuit every 0.1 second. 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 commands an immediate landing to 2nd gear.
* The TCM freezes transmission adaptive functions.



Conditions for Clearing the DTC

DTC P2534 is a type A DTC.


Reference Information
Schematic Reference

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

Component Connector End Views
Electrical Information Reference

* Circuit Testing
* Connector Repairs
* Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information
DTC Type Reference

* Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
* Diagnostic Trouble Code (DTC) List/Type (Diagnostic Trouble Code Descriptions)

Special Tools

* J 35616 GM Terminal Test Kit
* J 44152 Jumper Harness (20 pins)



Circuit/System Verification

Start and idle the engine. Using the scan tool, select the Ignition Voltage parameter on the scan tool. The Ignition Voltage parameter should be between 12.0-14.5 volts.


Circuit/System Testing

1. Remove the TRANS fuse. Inspect the fuse for an open.

• If the fuse is open, test the ignition 1 voltage circuit for a short to ground.

2. Disconnect the TCM connector. Turn ON the ignition, with the engine OFF. Using the J 35616 GM terminal test kit, measure the voltage at the ignition 1 voltage circuit. The voltage should be near battery voltage.

• If the voltage is below the specified value, test the ignition 1 voltage circuit for an open or high resistance.

3. If all circuits and connections test normal, replace the TCM.



Component Testing

Verify that there is near battery voltage on the ignition 1 voltage circuit at the TCM.


If the voltage is not near the specified value, repair the short to ground, open, or high resistance in the ignition 1 voltage circuit.


Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.


Control Module References for TCM replacement, setup, and programming.