GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    • Diagnostic Procedure Instructions provide an overview of each diagnostic category.

DTC Descriptors

DTC P0562: System Voltage Low

DTC P0563: System Voltage High

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Ignition 1 Voltage

P2534

P2534

--

P0562, P0563

Ignition 0 Voltage

--

--

--

P0562, P0563

Battery Positive Voltage

--

--

--

P0562, P0563

Typical Scan Tool Data

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Operating Conditions: Engine running in PARK, normal operating temperature

Parameter Normal Range: 12.5-14.5-volts

Ignition Voltage

0-volts

0-volts

12.5-14.5-volts

Circuit/System Description

The transmission control module (TCM) continuously monitors the system voltage on the ignition voltage and the battery voltage circuits. Lower than normal or higher than normal voltage may not operate the transmission control solenoids properly. Improper solenoid operation may cause erratic transmission operation and may result in internal transmission damage.

Conditions for Running the DTC

P0562

The engine speed is 1,200 RPM for greater than 5 seconds.

P0563

The ignition is ON.

Conditions for Setting the DTC

P0562

The TCM detects system voltage of 11-volts or less for 10 seconds.

P0563

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

Action Taken When the DTC Sets

DTC P0562 and P0563 are type C DTCs.

Conditions for Clearing the DTC

DTC P0562 and P0563 are type C DTCs.

Reference Information

Schematic Reference

Automatic Transmission Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Transmission General Description

Electrical Information Reference

    • Circuit Testing
    • Connector Repairs
    • Testing for Intermittent Conditions and Poor Connections
    • Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Ignition ON, observe the Ignition 1 Signal parameter with the scan tool. The Ignition 1 Signal parameter should read between 12.0-14.5-volts.

Circuit/System Testing

  1. Measure the voltage at the battery terminals and compare it with the Ignition 1 Signal parameter on the scan tool. Verify that battery and Ignition 1 signal readings do not differ greater than 1.0 volt.
  2. If greater than 1.0 volt, test the TCM ignition 1 and ground circuits for high resistance. If the circuits test normal, replace the TCM.
  3. Refer to Charging System Test.

Repair Instructions

  1. Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
  2. Refer to Control Module References for TCM replacement, setup, and programming.