Diagnostic Instructions
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. Improper solenoid
operation may cause erratic transmission operation, which may result in internal damage.
Conditions for Running the DTC
| • | The engine speed is greater than 500 RPM. |
| • | Ignition voltage is between 8-18 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
Connector End View Reference
DTC Type Reference
Electrical Information Reference
Circuit/System Testing
Clear the DTC and operate the vehicle under the conditions for running and setting the DTC.
| ⇒ | If the DTC resets, test the TCM ignition 1 voltage circuit for battery positive voltage at the TCM 16-way connector. |
| ⇒ | If the voltage is less than battery voltage, test the Ignition 1 voltage circuit for an open or short to ground and repair the circuit as necessary. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.
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