Diagnostic Instructions
DTC Descriptor
DTC P0562: System Voltage Low
DTC P0563: System Voltage High
DTC P2534: Ignition 1 Switch Circuit Low Voltage
Circuit/System Description
The transmission control module (TCM) requires a switched ignition voltage input to operate. The TCM continuously monitors the ignition voltage.
Conditions for Running the DTC
P0562 or P0563
| • | Engine Run time is greater than 10 seconds. |
| • | Engine speed is greater than 450 RPM. |
P2534
| • | Battery voltage is between 9-18 V. |
| • | Engine Run time is greater than 5 seconds. |
| • | Engine speed is greater than 200 RPM. |
Conditions for Setting the DTC
P0562
This DTC sets when the TCM detects ignition voltage greater than 5 V and less than a threshold voltage based on transmission fluid temperature for greater than 25 seconds and DTC P2534 is not active. Threshold is 5 V for temperatures
below -60°C, 8 V at 0°C, and 9 V for temperatures above 20°C.
P0563
This DTC sets when the TCM detects ignition voltage above 18 V, 60 percent of the time, for a 1 second interval.
P2534
This DTC sets when the TCM detects ignition voltage below 5 V for 30 seconds.
Action Taken When the DTC Sets
P0562
| • | The TCM does not request the engine control module (ECM) to illuminate the malfunction indicator lamp (MIL). |
| • | The TCM may not power up. |
| • | DTC P0562 is stored in TCM history. |
P0563
| • | The TCM does not request the ECM to illuminate the MIL. |
| • | DTC P0563 is stored in TCM history. |
P2534
| • | The TCM requests the ECM to illuminate the MIL. |
| • | DTC P2534 is stored in TCM history. |
Conditions for Clearing the DTC
P0562 and P0563
DTCs P0562 and P0563 are Type C DTCs.
P2534
DTC P2534 is a Type A DTC.
Diagnostic Aids
| • | A defective vehicle battery may allow DTC P0562 to set. |
| • | A defective vehicle charging system may allow DTCs P0562, P0563 or P2534 to set. |
| • | You may have to drive the vehicle in order to experience a condition. |
| • | Although this DTC could indicate an internal voltage condition within the TCM, in most cases, the TCM is not at fault. Investigate thoroughly prior to replacing the TCM. |
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Engine running, accessories OFF, measure and record the battery voltage at the battery terminals. The reading should be between 12.6 and 15 V.
- Observe the scan tool TCM ignition voltage parameter. The reading should be between 12.6 and 15 V.
- 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
Note: You must perform the Circuit/System Testing first.
- Ignition OFF, disconnect the harness connector at the TCM.
- Ignition OFF, test for less than 3 ohms between ground circuit terminal 9 and battery ground, and also ground circuit terminal 69 and battery ground.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
- Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 63 and ground.
| ⇒ | If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If circuit tests normal, replace the TCM. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for TCM replacement, setup, and programming.
Repair Verification
If another DTC is present, refer to
Diagnostic Trouble Code (DTC) List - Vehicle and perform the appropriate diagnostic procedure.
