GM Service Manual Online
For 1990-2009 cars only

Object Number: 1578851  Size: MF
Master Electrical Component List
Automatic Transmission Controls Schematics
OBD II Symbol Description Notice
Control Module References

Circuit Description

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.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0563 System Voltage High

Conditions for Running The DTC

The ignition is ON.

Conditions for Setting The DTC

The TCM detects system voltage is 18 volts or greater for 10 seconds.

Action Taken When the DTC Sets

    • The TCM does not request the ECM to illuminate the malfunction indicator lamp (MIL).
    • 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 DTC

    • A scan tool can clear the 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 below refer to the step numbers on the diagnostic table.

  1. This step tests the charging system voltage with a minimal load.

  2. This step obtains the ignition voltage measurement reported by the TCM.

Step

Action

Values

Yes

No

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Important: 

       • Before clearing the DTC, use the scan tool in order to record the Failure Records. Using the Clear Eng./Trans. DTC Info function erases the Failure Records from the TCM.
       • Using the Clear Eng./Trans. DTC Info function erases stored DTCs in both the ECM and TCM.

  4. Record the Failure Records.
  5. Clear the DTC.
  6. Start the engine and allow the engine to warm up to normal operating temperature.

Is the battery charge indicator lamp ON?

--

Go to Diagnostic System Check - Vehicle

Go to Step 3

3

  1. Turn OFF all electrical accessories.
  2. Increase the engine speed to 2,000 RPM.
  3. Using the DMM, measure the voltage between the battery terminals. Record the measurement for reference.

Is the voltage within the specified range?

12.5-14.5 V

Go to Step 4

Go to Charging System Test

4

  1. Leave the engine running.
  2. Observe the Ignition Voltage on the scan tool.
  3. Increase the engine speed to 2,000 RPM.

Is the difference between the voltage displayed on the scan tool and the voltage measurement in Step 3 greater than the specified value?

1.0 V

Go to Step 6

Go to Step 5

5

Did DTC P0563 reset?

--

Go to Step 6

Go to Testing for Intermittent Conditions and Poor Connections

6

Replace the TCM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 7

--

7

Perform the following procedure in order to verify the repair:

  1. Select DTC.
  2. Select Clear Info.
  3. Operate the vehicle under the following conditions:
  4. • Start the engine.
    • Allow the engine to warm up to normal operating temperature.
    • Observe the Ignition Voltage on the scan tool.
    • TCM voltage must remain below 18 volts for 10 seconds.
  5. Select Specific DTC.
  6. Enter DTC P0563.

Has the test run and passed?

--

Go to Step 8

Go to Step 2

8

With the scan tool, observe the stored information, capture info and DTC info.

Does the scan tool display any DTCs that you have not diagnosed?

--

Go to Diagnostic Trouble Code (DTC) List - Vehicle

System OK