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 VoltageDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Ignition 1 Voltage | P2534 | P2534 | -- | P0562, P0563 |
Typical Scan Tool Data
Circuit | Normal | Short to Ground | Open/High Resistance | Short to Voltage |
|---|---|---|---|---|
Operating Conditions: Engine running in PARK, normal operating temperature Parameter Normal Range: 12.0-14.5 volts | ||||
Ignition Voltage | 12.0-14.5 volts | 0 volts | 0 volts | 12.0-14.5 volts |
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 transmission 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.
Conditions for Clearing the DTC
DTC P2534 is a Type A DTC.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics
Connector End View Reference
Description and operation
Transmission General Description
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Special Tools
J 35616 GM-Approved Terminal Test Kit
Circuit/System Verification
Ignition ON, observe the Ignition 1 Signal parameter with the scan tool. The Ignition 1 Signal parameter should read between 12.0-14.5 volts.
Circuit/System Testing
- Measure the voltage at the battery terminals and compare it with the Ignition 1 Signal parameter on the scan tool. Verify that battery and Ignition 1 signal readings do not differ more than 1.0 volt.
- Go to Charging System Test.
| ⇒ | If greater than 1.0 volt, test the Ignition 1 and ground circuits of the TCM for high resistance. If the circuits test normal replace the TCM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
Control Module References for TCM replacement, setup, and programming
