Powertrain Management
DTC P0563: System Voltage HighWiring Diagram:
Circuit Description
The Engine Control Module (ECM) monitors the ignition voltage on the ignition feed circuit to terminal C33 at the ECM. A system voltage Diagnostic Trouble Code (DTC) will set whenever the voltage is below a calibrated value.
Conditions for Setting the DTC
^ System voltage is greater than 16 V.
^ Ignition switch is turned to ON.
Action Taken When the DTC Sets
^ The Malfunction Indicator Lamp (MIL) will illuminate.
^ The ECM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records buffers.
^ A history DTC is stored.
Conditions for Clearing the MIL/DTC
^ The MIL will turn OFF after four consecutive ignition cycles in which the diagnostic runs without a fault.
^ A history DTC will clear after 40 consecutive warm up cycles without a fault.
^ The DTC(s) can be cleared by using the scan tool.
^ Disconnecting the ECM battery feed for more than 10 seconds.
Diagnostic Aids
If the DTC sets when an accessory is operated, check for a poor connection or excessive current draw.
Any circuitry, that is suspected as causing the intermittent complaint, should be thoroughly checked for the following conditions:
^ Backed-out terminals
^ Improper mating
^ Broken locks
^ Improperly formed
^ Damaged terminals
^ Poor terminal-to-wiring connections
^ Physical damage to the wiring harness
Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table.
1. The On-Board Diagnostic (OBD II) System Check prompts the technician to complete some basic checks and store the Freeze Frame and Failure Records data on the scan tool if applicable. This creates an electronic copy of the data taken when the malfunction occurred.
The information is then stored on scan tool for later reference.
2. This checks if the generator is malfunctioning under load conditions.
3. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM reprogramming.
4. If no malfunctions have been found at this point and no additional DTCs were set, refer to Diagnostic Aids for additional checks and information for additional checks and information. Diagnostic Aids
Step 1-6:
Troubleshooting