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 LowDTC P0563: System Voltage High
Diagnostic Fault Information
Circuit | Short to Ground | High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Ignition 1 Voltage | P2534 | P0562 | -- | P0562, P0563 |
Accessory Voltage | -- | -- | -- | P0562, P0563 |
Battery Positive Voltage | -- | P0562 | -- | P0562, P0563 |
Lower than normal voltage may be inadequate to operate the transmission control solenoids properly. Improper solenoid operation may cause erratic transmission operation which may result in internal damage. | ||||
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.
Conditions for Running the DTC
P0562
The engine speed is greater than 1,200 RPM for 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.
Diagnostic Aids
| • | DTC P0562 detects a unacceptable system voltage of less than or equal to 11 volts at the TCM. |
| • | DTC P0563 detects a unacceptable system voltage of greater than or equal to 18 volts at the TCM. |
| • | 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 a 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
Description and Operation Reference
Charging System Description and Operation
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Engine running, accessories OFF, measure and record the battery voltage at the battery terminals. The voltage should be between 12.0 and 15.0 volts.
- Ignition ON, engine OFF, accessories OFF, observe the Battery Voltage parameter on the scan tool. The Battery Voltage should be between 12.0 and 14.5 volts.
- Engine running, accessories OFF, observe the Ignition Voltage parameter on the scan tool. The Ignition Voltage should be between 12.0 and 14.5 volts.
- Increase the engine speed to 1,500 RPM. The Ignition Voltage parameter should remain between 12.0-14.5 volts.
- Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
| ⇒ | If the voltage is not within the specified range, refer to Charging System Test. |
| ⇒ | If the voltage is not within the specified range, refer to Charging System Test. |
| ⇒ | If the voltage is not within the specified range, refer to Charging System Test. |
| ⇒ | If the voltage is not within the specified range when the engine speed is increased, refer to Charging System Test. |
Circuit/System Testing
- Engine OFF, disconnect the TCM connector. Connect the negative probe of the DMM to a good ground.
- Ignition ON, engine OFF. Using the light blue 0.64 mm J 35616-64B probe, test for 11.0-14.5 V between the voltage circuit terminals listed below and the good ground.
- Compare the battery positive voltage value to the ignition 1 voltage value from step 3 above. The voltage drop between the circuits should be less than 0.2 volt.
- If all circuits and connections test normal, replace the TCM.
Important: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.
Important: When test probing TCM harness terminals, it is imperative to use the proper test probe from the most current version of the J 35616 GM terminal test kit. Use of the brown J 35616-6 (1.00 mm) PCM probe in a 0.64 mm terminal will deform the terminal, resulting in intermittent open conditions. The correct probe for TCM harnesses is the light blue 0.64 mm J 35616-64B probe.
| • | Battery positive voltage, TCM connector Terminal 32 |
| • | Ignition 1 voltage, TCM connector Terminal 31 |
| ⇒ | If 0 V, inspect the Powertrain Control Module ETC fuse, fuse 9, and the Powertrain Control Module Ignition fuse, fuse 14, located in the Underhood Fuse Block, for being open. If open, test the affected circuit for a short to ground. |
| ⇒ | If the fuse is not open, test the affected circuit for an open. |
| ⇒ | If the voltage drop is greater than 0.2 volt, repair the open or high resistance in the affected circuit. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for TCM replacement, setup, and programming
