P2536

DTC P2536

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 P2536
- Ignition Accessory Switch Circuit




Circuit/System Description

The transmission control module (TCM) continuously monitors the ignition accessory voltage circuit. A low ignition accessory voltage reading at the TCM will cause DTC P2536 to set.


Conditions for Running the DTC

* No Engine Speed Circuit Malfunction, DTC P0727.
* No Lost Communications with the ECM, DTC U0100.
* NO CAN Bus Reset Counter Overrun, DTC U2104.
* Engine speed is 400 RPM or greater.
* Not in Emergency Mode.



Conditions for Setting the DTC

The TCM detects that ignition accessory voltage is less than 8.68 volts for 20 seconds.


Action Taken When the DTC Sets

DTC P2536 is a Type A DTC.


Conditions for Clearing the DTC

DTC P2536 is a Type A DTC.


Diagnostic Aids

A charging system malfunction may cause variances in system voltage and set voltage related DTCs. Refer to Charging System Test .


Reference Information
Schematic Reference

Automatic Transmission Controls Schematics (Electrical Diagrams)
Connector End View Reference

* Electrical Center Identification Views
* Component Connector End Views
* Splice Pack Connector End Views
* Inline Harness Connector End Views

Electrical Information Reference

* Circuit Testing
* Connector Repairs
* Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs

DTC Type Reference

* Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
* Diagnostic Trouble Code (DTC) List/Type (Diagnostic Trouble Code Descriptions)

Scan Tool Reference

Control Module References for scan information.


Circuit/System Verification

Engine running, verify the transmission control module (TCM) scan tool ignition voltage parameter is greater than 8.68 volts.

If not greater than the specified range, refer to Charging System Test before performing Circuit/System Testing.



Circuit/System Testing

Important: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.



1. Ignition OFF, disconnect the C1 harness connector at the TCM.
2. Test for less than 1.0 ohm between ground circuit terminal 9 and ground.

• If greater than the specified value, test the ground circuit for an open/high resistance.

3. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 12 and ground.

• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, replace the TCM.

4. If all circuits test normal, replace the TCM.



Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.