DTC P2534
Diagnostic Instructions
DTC Descriptor
DTC P2534: Ignition On/Start Switch Circuit Low Voltage
Diagnostic Fault Information
Circuit
| Short to Ground
| Open/High Resistance
| Short to Voltage
| Signal Performance
|
Ignition 1 voltage
| P2534 open fuse
| P2534
| -
| P0562, P0563
|
Circuit/System Description
The transmission control module (TCM) continuously monitors the system voltage on the Ignition 1 voltage circuit. 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 control module (ECM) communicates that the engine is running through the controller area network (CAN).
Conditions for Setting the DTC
The TCM detects less than 6 volts on the ignition voltage circuit at the TCM for 7 seconds or greater.
Action Taken When the DTC Sets
| • | DTC P2534 is a Type A DTC. |
| • | The TCM turns OFF the high side driver. |
| • | The TCM turns OFF all solenoids. |
| • | The TCM commands maximum line pressure. |
| • | the TCM freezes transmission adaptive functions. |
| • | The TCM commands the torque converter clutch (TCC) OFF. |
| • | The TCM limits the transmission to reverse and 5th gear. |
| • | The TCM inhibits Tap up/Tap down/MUMD operation. |
Conditions for Clearing the DTC
DTC P2534 is a Type A DTC.
Diagnostic Aids
| • | Observe the driver information centre (DIC) messaging that would indicate the electrical system requires service. |
| • | Inspect for the following conditions: |
| - | Loose or damaged terminals at the generator |
| - | Loose or worn generator drive belt |
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Special Tools
DT-48616-10 Adapter Harness
Circuit/System Verification
- Engine ON, accessories OFF, measure and record the battery voltage at the battery terminals. The voltage should be between 12.6-15.0 volts.
- Observe the scan tool TCM Ignition Voltage parameter. The reading should be between 12.6-15.0 volts.
- After performing the above steps, verify that the DTC does not reset by operating the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions you observe from the Freeze Frame/Failure Records data. If the vehicle passes the Circuit/System Verification procedure, then STOP. Do not perform the Circuit/System Testing or Component Testing as this may result in an unnecessary part replacement. Refer to Testing for Intermittent Conditions and Poor Connections .
Circuit/System Testing
Note: You must perform the Circuit/System Verification first.
- Ignition OFF, disconnect the 14-way harness connector at the transmission.
- Connect the DT-48616-10 harness to the 14-way transmission harness connector.
- Test for less than 10 ohms between the ground circuit terminal 2 and ground.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
- Ignition ON, verify that a test lamp illuminates between the B+ and ignition circuit terminals listed below and ground.
| ⇒ | If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. |
- If all circuits test normal, replace the control solenoid valve assembly.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| © Copyright Chevrolet. All rights reserved |
| © Copyright Chevrolet. All rights reserved |
