VT25-E Automatic Transmission

VT25-E AUTOMATIC TRANSMISSION

DTC P0562

Test 1-8:

Test 9-14:

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. Lower than normal voltage may be inadequate to operate the transmission control solenoids properly. Improper solenoid operation may cause erratic ratio control operation, which may result in internal damage.

If the TCM detects low voltage for a number of samples, DTC P0562 sets, DTC P0562 is a type C DTC.

Conditions for Running The DTC
The engine speed is 1,500 RPM or greater.

Conditions for Setting The DTC
The TCM detects system voltage is 11 volts or less for 42 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 no longer inhibits shifting to between reverse and drive when moving.
^ 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 records this information as Failure Records.
^ The TCM stores DTC P0562 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
Inspect for the following conditions:
^ Loose or damaged terminals at the generator
^ Loose or worn generator drive belt
^ Inspect the connectors at the TCM, the transmission, and all other circuit connecting points for an intermittent condition.
^ Inspect the circuit wiring for an intermittent condition.

Test Description
The numbers refer to the step numbers on the diagnostic table.
4. This step tests the charging system voltage with a nominal load.
5. This step obtains the ignition voltage measurement reported by the TCM.
6. This step tests the voltage drop from the battery and ignition voltage input at the TCM.
10. This step tests the voltage drop from the ground terminals of the TCM to the ground terminal of the battery.