Diagnostic Instructions
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. |
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
.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics
Connector End View Reference
Electrical Information Reference
DTC Type Reference
Scan Tool Reference
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.
- Ignition OFF, disconnect the C1 harness connector at the TCM.
- Test for less than 1.0ohms of resistance between ground circuit terminal 9 and ground.
| ⇒ | If greater than the specified value, test the ground circuit for an open/high resistance. |
- 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. |
- If all circuits test normal, replace the TCM.
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
