P2537
DTC P2537
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptors
DTC P2537
- Ignition Accessory Switch Circuit Low Voltage
Diagnostic Fault Information
Circuit/System Description
With ignition in the accessory position or ignition ON, the BCM supplies a 12 volt wake up signal on the Ignition Accessory/Run circuit. The transmission control module (TCM) continuously monitors the Accessory/Run circuit. This wake up signal allows the TCM to power up and start functioning.
Conditions for Running the DTC
Engine is running.
Conditions for Setting the DTC
The TCM does not detect 6 volts or greater on the accessory wake up circuit within 32 seconds following startup.
Action Taken When the DTC Sets
DTC P2537 is a Type C DTC.
Conditions for Clearing the DTC
DTC P2537 is a Type C DTC.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics Electrical Diagrams
Connector End View Reference
* Component Connector End Views Sunshade - Left (D6I)
* Inline Harness Connector End Views X100
Description and Operation
* Transmission Component and System Description Transmission Component and System Description
* Electronic Component Description Electronic Component Description
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Control Module References for scan tool information
Special Tools
DT-48616-10 - Adapter Harness
For equivalent regional tools, refer to Special Tools 6T30/6T40/6T45/6T50 - Automatic Transmission.
Circuit/System Verification
1. Verify with a scan tool that there are no DTCs set in the BCM.
• If DTCs are set in the BCM
Refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.
• If DTCs are not set in the BCM
2. Ignition switch in the Accessory position, verify the scan tool BCM Accessory parameter displays Active.
• If the Accessory parameter does not display Active
Refer to Power Mode Mismatch Power Mode Mismatch.
• If the Ignition Switch Accessory Signal parameter displays Active
3. Ignition switch in the Run position, verify the scan tool BCM Ignition Switch Accessory Signal parameter displays Active.
• If the Ignition Switch Accessory Signal parameter does not display Active
Refer to Power Mode Mismatch Power Mode Mismatch.
• If the Ignition Switch Accessory Signal parameter displays Active
4. Ignition ON, clear the BCM and TCM of all DTCs.
5. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down.
6. Engine running in park position for 1 minute. Verify DTC P2537 is not set in the TCM.
• If DTC P2537 is set
Refer to Circuit/System Testing below.
• If DTC P2537 is not set
7. 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 Testing for Intermittent Conditions and Poor Connections.
Circuit/System Testing
1. Ignition OFF, and all vehicle systems OFF, disconnect the X1 14-way harness connector at the transmission.
2. Connect the DT-48616-10 - harness to the vehicle wire harness X1 14-way transmission connector.
3. Ignition ON, verify a test lamp illuminates between terminal 13 and ground at the transmission case.
• If the test lamp does not illuminate and the circuit fuse is good
1. Ignition OFF, and all vehicle systems OFF.
2. Test for less than 2 ohm in the Accessory voltage circuit end to end.
• If 2 ohm or greater, repair the open/high resistance in the circuit.
• If less than 2 ohm, replace the K9 body control module
• If the test lamp does not illuminate and the circuit fuse is open
1. Ignition OFF.
2. Test for infinite resistance between the ignition accessory circuit and ground.
• If less than infinite resistance, repair the short to ground in the circuit.
• If infinite resistance, replace fuse and retest. If fuse opens again, refer to Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections.
• If the test lamp illuminates
4. Replace the Q8 control solenoid valve assembly
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Before replacing the TCM, perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection Control Solenoid Valve and Transmission Control Module Assembly Inspection.
* Refer to Control Module References Control Module References for control solenoid valve assembly replacement, setup, and programming.
* Perform the Transmission Adaptive Values Learn Programming and Relearning following all transmission related repairs.