Circuit Description
The engine control module (ECM) checks the system voltage to make sure that the voltage stays within the proper range. Damage to components and incorrect input can occur when the voltage is out of range. The ECM monitors the system voltage over an extended length of time. If the ECM detects an excessively high system voltage, DTC P0563 will set.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0563 System Voltage High
Conditions for Running the DTC
System voltage is between 9.5-18 volts.
Conditions for Setting the DTC
| • | The ECM detects a system voltage above 18 volts for 5 seconds. |
| • | Engine speed is above 1,300 RPM. |
| • | Vehicle speed is above 20 km/h (12 mph). |
Action Taken When the DTC Sets
| • | The ECM will not illuminate the charge indicator. |
| • | The ECM will not illuminate the malfunction indicator lamp (MIL). |
| • | The ECM will store conditions which were present when the DTC set as Failure Records data only. |
Conditions for Clearing the DTC
| • | The ECM will command the message OFF after one trip in which the diagnostic test has been run and passed. |
| • | The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction. |
| • | The DTC can be cleared by using the scan tool Clear DTC Information function. |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Connector End View Reference: Inline Harness Connector End Views in Wiring Systems or Engine Control Module Connector End Views in Engine Controls - 3.0L (L81) | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
2 |
Does the scan tool indicate that DTC P0563 has passed this ignition cycle? | -- | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 |
3 |
Does the scan tool indicate that the Ignition 1 Signal parameter is less than the specified value? | 17.5 V | Go to Step 5 | Go to Step 4 |
4 | Measure the voltage at the battery terminals and compare it with the Ignition 1 parameter in the ECM data list. Are the battery voltage and ECM Ignition 1 readings different by more than the specified value? | 0.5 V | Go to Step 5 | Go to Charging System Test |
5 |
Important: The replacement engine control module (ECM) must be programmed. Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 6 | -- |
6 |
Does the scan tool indicate that DTC P0563 failed this ignition? | -- | Go to Step 3 | System OK |
