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 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.
Conditions for Running the DTC
* The engine is running.
* Ignition voltage is between 8.6 volts and 19.0 volts.
Conditions for Setting the DTC
The TCM detects 2 volts or less on the ignition 1 voltage circuit at the TCM for 10 seconds or more.
Action Taken When the DTC Sets
* DTC P2534 is a Type A DTC.
* The TCM turns OFF all high side drivers.
* The TCM turns OFF all solenoids.
* The TCM commands maximum line pressure.
* the TCM freezes transmission adaptive functions.
* The TCM commands the TCC OFF.
* The TCM allows the vehicle to operate in transmission protection mode.
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.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views
Description and Operation
Transmission General Description (Transmission General Description)
Electrical Information Reference
* Circuit Testing
* Connector Repairs
* Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Special Tools
DT-47825-20 Adapter Harness
Circuit/System Verification
1. Engine running, accessories OFF, measure and record the battery voltage at the battery terminals. The voltage should be between 12.6 and 15.0 volts.
• If not within the specified range, refer to Charging System Test (Acadia or Enclave) Charging System Test (OUTLOOK) .
2. Observe the scan tool TCM Ignition Voltage. The reading should be between 12.6 and 15.0 volts.
3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
1. Ignition OFF, disconnect the 20-way harness connector at the transmission.
2. Connect the DT-47825-20 to the 20-way transmission harness connector.
3. Test for less than 10 ohms of resistance between the ground circuit terminals listed below and ground:
* Terminal 1
* Terminal 18
• If greater than the specified range, test the ground circuit for an open/high resistance.
4. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 15 and ground.
• If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
5. If all circuits test normal, replace the control solenoid (w/body and TCM) valve assembly.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Important:
* Perform the Service Fast Learn Adapts (Programming and Relearning) following all transmission related repairs.
* Before replacing the TCM, perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection (Control Solenoid Valve and Transmission Control Module Assembly Inspection) .
Refer to Control Module References for control solenoid (w/body and TCM) valve assembly replacement, setup, and programming.