Circuit Description
The transmission control module (TCM) continuously monitors the system voltage on the Ignition 1 circuits. Higher than normal voltage may cause the solenoids inside the transmission to operate improperly or damage solid-state components inside the TCM.
When the TCM detects high voltage, DTC P0563 sets. DTC P0563 is a type A DTC.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0563 System Voltage High
Conditions for Running The DTC
| • | No engine speed signal DTC P0727 |
| • | No Communications DTC U2104 or U0100 |
| • | Trans. Protection Mode is OFF. |
| • | Transmission input shaft speed is greater than 400 RPM. |
Conditions for Setting The DTC
The TCM detects system voltage is greater than 18 volts for 20 seconds.
Action Taken When the DTC Sets
| • | The TCM requests the powertrain control module (PCM) to illuminate the malfunction indicator lamp (MIL). |
| • | The TCM turns the Trans. Protection Mode ON. |
| • | The transmission will operate in 5th gear when the transmission is shifted into D or I range and 2nd gear when shifted into L range. |
| • | The line pressure is at maximum. |
| • | The torque converter clutch (TCC) is disabled. |
| • | The TCM freezes the transmission adaptive functions. |
| • | The PCM records the operating conditions when the Condition for Setting the DTC are met. The PCM stores this information as Freeze Frame and Failure Records. |
| • | The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Record. |
| • | The TCM stores DTC P0563 in TCM history. |
Conditions for Clearing the MIL/DTC
| • | The TCM turns OFF the MIL request during the third consecutive trip in which the diagnostic test runs and passes. |
| • | A scan tool can clear the MIL/DTC. |
| • | The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an 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
| • | Observe the driver information center (DIC) messaging that would indicate the electrical system requires service. |
| • | 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.
-
This step tests the charging system voltage with a minimal load.
-
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 | |||||||||
2 |
Important:
Is the charge indicator light ON? | -- | Go to Step 3 | |||||||||
Is the voltage within the specified range? | 12.5-14.5 V | Go to Step 4 | Go to Charging System Test | |||||||||
Is the difference between the voltage displayed on the scan tool and the voltage measurement in Step 4 greater than the specified value? | 1.0 V | Go to Step 6 | Go to Step 5 | |||||||||
5 | Did 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. Is the action complete? | -- | Go to Step 7 | -- | ||||||||
7 | Perform the following procedure in order to verify the repair:
Does the DTC reset? | -- | ||||||||||
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? | -- | System OK |
