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
Component Connector End Views
Electrical Information Reference
DTC Type Reference
Scan Tool Reference
Control Module References
for scan tool 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.
- Ignition OFF, disconnect the C1 harness connector at the TCM.
- 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. |
- 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.
