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For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2005 🢒 GMC C Sierra - 2WD 🢒 Transmission/Transaxle 🢒 Automatic Transmission - Allison 🢒 DTC P0563

Circuit Description

The transmission control module (TCM) requires ignition voltage to operate correctly. The voltage signal should be direct from the ignition switch to avoid any interference.

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 components are powered and ignition voltage is greater than 9.0 volts and less than 18 volts.
    • The engine speed is greater than 450 RPM for 1.0 second.

Conditions for Setting the DTC

DTC P0563 sets when the TCM detects a voltage greater than 18 volts for 6 out of 10 seconds.

Action Taken When the DTC Sets
    • The TCM does not illuminate the malfunction indicator lamp (MIL).
    • The transmission fails to hydraulic default.
    • DTC P0563 will be stored in TCM history.
    • The TCM inhibits torque converter clutch (TCC) engagement.
    • The TCM freezes shift adapts.

Conditions for Clearing the DTC

A scan tool can clear the code from TCM history. The TCM automatically clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without failure.

Diagnostic Aids
    • Inspect for the presence of aftermarket accessories, such as a remote starter, etc. Depending on how these aftermarket accessories are installed, they may interfere with the required voltage for proper operation of the transmission.
    • Inspect the wiring for poor electrical connections at the TCM. Inspect for the following conditions:
       - A bent terminal
       - A backed-out terminal
       - A damaged terminal
       - Poor terminal tension
       - A chafed wire
       - A broken wire inside the insulation
    • When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change.
    • You may have to drive the vehicle in order to experience a condition.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step tests B+ voltage.

    2.

  2. This step tests the status of the charging system.

Step

Action

Value

Yes

No

Schematic Reference: Automatic Transmission Controls Schematics

1

Did you perform the Diagnostic System Check - Vehicle?

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Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2
  1. Install the 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 Freeze Frame and Failure Records for reference. The Clear Info function will erase the data.

  3. Record the DTC Freeze Frame and Failure Records.
  4. Clear the DTC.
  5. Using a DMM, measure and record voltage at the battery terminals.

Is voltage within the specified value?

B+

Go to Step 3

Go to Step 4

3

Start the engine and observe the charge indicator on the instrument cluster. Refer to Charging System Test in Engine Electrical.

Does the charge indicator display voltage higher than specified value?

18 V

Go to Step 5

Go to Step 6

4

Replace the battery, or resolve the battery condition. Refer to Battery Inspection/Test in Engine Electrical.

Did you resolve the battery condition or replace the battery?

--

Go to Step 6

--

5

Repair the charging system. Refer to Charging System Test or Generator Replacement in Engine Electrical.

Did you complete the repair?

--

Go to Step 6

--

6

Perform the following procedure in order to verify the repair:

  1. Clear the DTC.
  2. Using the scan tool, monitor TCM voltage.
  3. Select Specific DTC.
  4. Enter DTC P0563.

Has the test run and passed?

--

System OK

Go to Step 1