For 1990-2009 cars

### 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 provides an overview of each diagnostic category.

### DTC Descriptor

DTC P0562: System Voltage Low
DTC P0563: System Voltage High

### Circuit/System Description

The transmission control module (TCM) continuously monitors the system voltage on the Ignition 1 and the battery circuits. Lower than normal voltage may be inadequate to operate the transmission control solenoids properly. Improper solenoid operation may cause erratic transmission operation and tie-up conditions, which may result in internal damage.

### Conditions for Running the DTC

#### P0562

The engine speed is at least 1,200 RPM for 10 seconds.

#### P0563

The ignition is ON for 10 seconds.

### Conditions for Setting the DTC

#### P0562

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

#### P0563

The TCM detects system voltage is 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.

### Diagnostic Aids

• | Observe the driver information center (DIC) messaging that would indicate the electrical system requires service.

• | Inspect for loose or damaged terminals at the generator.

• | Inspect for loose or worn generator drive belt.

• | 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.

### Reference Information

#### Schematic Reference

Automatic Transmission Controls Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Transmission General Information

#### 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

Transmission Control Module Scan Tool Information

### Circuit/System Verification

Start the engine in PARK and observe the Ignition Voltage parameter on the scan tool. The Ignition Voltage should be between 12-14.5 volts.

### Circuit/System Testing

1. Start the engine and observe the Ignition Voltage parameter with a scan tool. The Ignition Voltage parameter should be between 12-14.5 volts.

⇒ | If the voltage is not within the specified range, refer to Charging System Test .

2. Increase the engine speed to 1,500 RPM. The Ignition Voltage parameter should remain between 12-14.5 volts.

⇒ | If the voltage is not within the specified range when the engine speed is increased, refer to Charging System Test .

3. Turn OFF the ignition. Disconnect the TCM connector. Probe the battery positive voltage and the ignition 1 voltage circuits of the TCM connector with the ground probe of the DMM. Connect the positive lead of the DMM to the battery positive terminal. Turn ON the ignition, with the engine OFF. Measure the voltage drop for each circuit. The voltage drop should be less than 0.5 volts.

⇒ | If the voltage drop is greater than 0.5 volts, repair the high resistance in the affected circuit.

4. Turn OFF the ignition. Using the positive probe of the DMM, probe the ground circuits of the TCM connector. Connect the negative lead of the DMM to the battery ground terminal. Observe and record the voltage measurements. The voltage drop should be less than 0.2 volts.

⇒ | If the voltage drop is greater than 0.2 volts, repair the open or high resistance in the affected circuit.

⇒ | If all circuits and connections test normal, replace the TCM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• | Ensure the battery voltage is between 12-14.5 volts.

• | Control Module References for TCM replacement, setup, and programming.