P2536

DTC P2536

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 Descriptor
DTC P2536
- Ignition Accessory Switch Circuit

Circuit/System Description

The transmission control module (TCM) will wake up from sleep mode when a voltage greater than 5 V is detected on the switched ignition input or accessory/wake up input. The Body Control Module (BCM) provides voltage to the TCM accessory/wake up input. After wake up, the TCM will not go into sleep mode until the accessory/wake up input and ignition input are less than 5 V.

Conditions for Running the DTC

* DTC 2536 is not set.
* Battery voltage is between 9-18 V.
* Engine speed is greater than 200 RPM for 5 seconds.

Conditions for Setting the DTC

The TCM detects that the accessory/wake up voltage is less than 5 volts for 1 minute.

Action Taken When the DTC Sets

DTC P2536 is a Type C DTC.

Conditions for Clearing the DTC

DTC P2536 is a Type C DTC.

Diagnostic Aids

You may have to drive the vehicle in order to experience a condition.

Reference Information
Schematic Reference

Automatic Transmission Controls Schematics (Allison - Automatic Transmission)
Connector End View Reference

* Component Connector End Views (Connector End Views By Name)
* Inline Harness Connector End Views (Connector End Views By Number)

Description and Operation

* Transmission General Description (Transmission General Description)
* 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

Circuit/System Verification

1. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down.
2. Ignition ACCESSORY, verify that a scan tool can communicate with the TCM.
3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the TCM.
2. Ignition ACCESSORY, test for greater than 5 V on the signal circuit between the TCM harness connector terminal 43 and ground.

• If less than the specified value, test the signal circuit for a short to ground, or an open/high resistance. If the circuit tests normal, replace the BCM.

3. If the signal circuit tests normal, replace the TCM.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Wiring Harness Replacement (Allison - Automatic Transmission)
* Control Module References (Control Module References) for TCM replacement, setup, and programming

Repair Verification

If another DTC is present, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code (DTC) List - Vehicle) and perform the appropriate diagnostic procedure.