Automatic Transmission - AF33-5
DTC P2534
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview)provides an overview of each diagnostic category.
DTC Descriptor
DTC P2534
- Ignition 1 Switch Circuit Low Voltage
Circuit/System Description
The transmission control module (TCM) continuously monitors the ignition voltage circuit. A low ignition voltage reading at the TCM will cause DTC P2534 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.
* Battery Voltage is greater than 9.0 volts.
* Not in Emergency Mode.
Conditions for Setting the DTC
The TCM detects that ignition voltage is less than 8.68 volts for 20 seconds.
Action Taken When the DTC Sets
* DTC P2534 is a Type A DTC.
* The transmission will operate in 5th gear in D or M range, 2nd gear in L range.
Conditions for Clearing the DTC
DTC P2534 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 (Charging System Test).
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics (Electrical Diagrams)
Connector End View Reference
* Electrical Center Identification Views (Application and ID)
* Component Connector End Views (Connector Views)
* Splice Pack Connector End Views (Connector Views)
* Inline Harness Connector End Views (Connector Views)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
DTC Type Reference
* Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
* Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code Descriptions)
Scan Tool Reference
Control Module References (Programming and Relearning)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 (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 11 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 (Verification Tests) after completing the diagnostic procedure.