VT25-E Automatic Transmission

VT25-E AUTOMATIC TRANSMISSION

DTC P0563

Test 1-6:

Test 7-8:

Circuit Description with VT25-E Automatic Transmission
The transmission control module (TCM) samples the system voltage on the Ignition 1 circuit every 0.1 seconds. Higher than normal voltage may cause the transmission control solenoids to operate improperly or damage the solid-state components inside the TCM.

If the TCM detects high voltage for a number of samples, DTC P0563 sets. DTC P0563 is a type C DTC.

Conditions for Running The DTC
The engine is running.

Conditions for Setting The DTC
The TCM detects system voltage is 18 volts or greater for 43 out of 50 samples.

Action Taken When the DTC Sets
^ The TCM does not request the ECM to illuminate the malfunction indicator lamp (MIL).
^ SERVICE VEHICLE message displays on the driver information center (DIC).
^ The TCM discontinues use of the closed loop ratio control algorithm. This causes the speed ratio to be defaulted and possibly not accurate. The resulting open loop control may or may not provide optimum ratio performance.
^ The TCM inhibits TCC engagement.
^ The TCM commands maximum line pressure.
^ The TCM turns power off to the TCC enable solenoid valve.
^ The TCM discontinues torque management.
^ The TCM freezes garage shift transmission adaptive functions.
^ The TCM freezes main line pressure transmission adaptive functions.
^ The TCM freezes torque converter clutch (TCC) transmission adaptive functions.
^ The TCM records the operating conditions when the Conditions for Setting the DTC are met.
^ The TCM stores this information as Failure Records.
^ The TCM stores DTC P0563 in TCM history.

Conditions for Clearing the DIC/DTC
^ The TCM clears the DIC message when the condition no longer exists.
^ A scan tool can clear the DIC/DTC.
^ The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non-emission related diagnostic fault occurring.
^ The TCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the TCM.

Diagnostic Aids
^ Use the scan tool in order to inspect all other modules for voltage related DTCs.
^ Running the engine with a battery charger attached may cause DTC P0563 to set.
- Inspect the charging circuit for high resistance.
- Inspect the vehicle battery for open or sulfated cells.

Test Description
The numbers refer to the step numbers on the diagnostic table.
3. This step tests the charging system voltage with a minimal load.
4. This step obtains the ignition voltage measurement reported by the TCM.