• | 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. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Ignition 1 Voltage | P2534 | P2534 | -- | P0562, P0563 |
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 |
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.
The engine is running.
The TCM detects an open or short to ground on the ignition 1 voltage circuit.
• | 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. |
DTC P2534 is a type A DTC.
Automatic Transmission Controls Schematics
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
• | J 35616 GM Terminal Test Kit |
• | J 44152 Jumper Harness (20 pins) |
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.
⇒ | If the fuse is open, test the ignition 1 voltage circuit for a short to ground. |
⇒ | If the voltage is below the specified value, test the ignition 1 voltage circuit for an open or high resistance. |
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.
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for TCM replacement, setup, and programming.