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 Voltage | P2534 | P2534 | P2534 | P2534 |
Typical Scan Tool Data
Circuit | Short to Ground | Open/High Resistance | Short to Voltage |
|---|---|---|---|
Operating Conditions: Key ON Parameter Normal Range: 8-18 volts | |||
IGN | 0 volts | 0 volts | B+ |
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 TCM is communicating on the GMLAN serial data bus.
Conditions for Setting the DTC
The TCM detects less than 2 volts on the IGN voltage circuit at the TCM for greater than 10 seconds.
Action Taken When the DTC Sets
| • | P2534 is a Type A DTC. |
| • | The TCM turns OFF all solenoids. |
| • | The TCM commands maximum line pressure. |
| • | The TCM freezes transmission adaptive functions. |
Conditions for Clearing the DTC
P2534 is a Type A DTC.
Diagnostic Aids
| • | Ensure the transmission pass through connector and harness terminals are clean and not damaged, and the charging system is functioning correctly. |
| • | The transmission 24-way inline harness connector must be disconnected prior to disconnecting the transmission 16-way inline harness connector |
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics
Connector End View Reference
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Circuit/System Testing
- Ignition OFF, disconnect the transmission 24-way inline harness connector, then the transmission 16-way in line harness connector at the transmission, verify that a test lamp does not illuminate between the ignition voltage circuit terminal 12 and ground.
- Ignition ON, verify that a test lamp illuminates between the ignition voltage circuit terminal 12 and ground.
| ⇒ | If the test lamp illuminates, test the IGN voltage circuit for a short to voltage. |
| ⇒ | If the test lamp does not illuminate, test the ignition voltage circuit for a short to ground or an open/high resistance. |
| ⇒ | If the circuit tests normal replace the control solenoid (w/body and TCM) valve assembly. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for control solenoid (w/body and TCM) valve assembly replacement, setup, and programming.
