Circuit Description
The engine control module (ECM) continuously monitors the system voltage. The ECM monitors the system voltage to make sure that the voltage stays within the proper range. If the ECM detects an excessively high system voltage, DTC P0563 will set. A high voltage condition may cause a stalling condition or other driveability concerns.
Conditions for Running the DTC
| • | The engine run time is more than 20 seconds. |
| • | Engine running above 1,200 RPM. |
| • | Vehicle speed above 8 km/h (5 mph). |
Conditions for Setting the DTC
| • | The ECM senses the system voltage is above 19 volts. |
| • | All of the conditions are present for 5 seconds. |
Action Taken When the DTC Sets
| • | The ECM stores DTC P0563 in the ECM memory when the diagnostic runs and fails. |
| • | The ECM will record the operating conditions at the time the diagnostic fails. The ECM stores this information in Failure Records. |
| • | The ECM disables most outputs. |
| • | The transmission defaults to a predetermined gear. |
| • | The torque converter clutch (TCC) operation is inhibited. |
| • | The instrument panel cluster (IPC) displays a message. |
| • | The malfunction indicator lamp (MIL) will not illuminate. |
Conditions for Clearing the DTC
| • | The Conditions for Setting the DTC are no longer present. |
| • | A history DTC will clear after 40 malfunction free ignition cycles. |
| • | The ECM receives the clear code command from the scan tool. |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: Starting and Charging Schematics Connector End View Reference: Engine Electrical Connector End Views | ||||
1 | Did you perform the Engine Electrical Diagnostic System Check? | -- | Go to Step 2 | |
2 |
Is the battery voltage less than the specified value? | 19 V | Go to Step 4 | Go to Step 3 |
3 | Replace the generator. Refer to Generator Replacement . Is the action complete? | -- | Go to Step 5 | -- |
4 | Replace the ECM. Refer to Engine Control Module Replacement/Restore Fuel Rate Data in Engine Controls-7.8L. Is the action complete? | -- | Go to Step 5 | -- |
5 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
