DTC P0563 System Voltage High. Cadillac DeVille 1998

For 1990-2009 cars only

Makes 🢒 Cadillac 🢒 1998 🢒 DeVille 🢒 Engine 🢒 Engine Controls - 4.0L and 4.6L 🢒 DTC P0563 System Voltage High

Engine Controls Components
Cell 20: PCM Power and Grounds
OBD II Symbol Description Notice
ESD Notice

Circuit Description

The PCM monitors the system voltage on CKT 639 to PCM connector C1 terminal 19 (Ignition 1). If the voltage is 16 volts or greater for 6 seconds, DTC P0563 is set.

Conditions for Running the DTC

Tested continuously.

Conditions for Setting the DTC

System (ignition 1) voltage more than 16 volts for 6 seconds.

Action Taken When the DTC Sets

•	The Malfunction Indicator Lamp (MIL) will not illuminate.

•	The PCM will command a message to be displayed.

•	The PCM may record operating conditions at the time the diagnostic fails. This information will be stored in the Failure Records.

Conditions for Clearing the Message/DTC

•	The PCM will turn the message OFF after one run and pass of the diagnostic test.

•	A History DTC will clear after forty consecutive warm-up cycles with no failures of any non-emission related diagnostic test.

•	A Last Test Failed (current) DTC will clear when the diagnostic runs and does not fail.

•	Use a scan tool to clear DTCs.

•	Interrupting PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Clearing Diagnostic Trouble Codes in PCM Description and Operation.

Diagnostic Aids

Normal running system voltage is 13 to 15.0 volts. A loose or faulty connection at generator L terminal may cause DTC P0563 to set intermittently.

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

If ignition voltage and IPC battery voltage are within 0.5 volt of each other, there may be a system voltage problem. If they are not within 0.5 volt of each other, find out why the PCM is different.

Checking if PCM ignition voltage is actually displaying system voltage.

Checking for an open or high resistance in the ignition feed circuit.

Step	Action	Value(s)	Yes	No
1	Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?	--	Go to Step 2	Go to Powertrain On Board Diagnostic (OBD) System Check
2	Start the engine. Connect a scan tool. View the Ignition 1 voltage display. Compare the Ignition 1 display to the battery voltage displayed by the IPC message center. Are PCM and IPC voltage readings different by more than the value specified?	0.5 volts	Go to Step 3	Go to Charging System Check in Engine Electrical
3	Using DMM J 39200 measure voltage to ground on the PCM fuse (installed). Are the Ignition 1 and DMM voltage readings different by more than the value specified?	0.5 volts	Go to Step 4	Go to Charging System Check in Engine Electrical
4	Check for high resistance in the ignition feed circuit. Was a high resistance found and repaired?	--	Go to Powertrain Control Module Diagnosis	Go to Step 5
5	Check PCM terminal contact at connector C1 terminal 19 and connector C2 terminal 37. Repair terminal contact if needed. Was terminal contact repaired?	--	Go to Powertrain Control Module Diagnosis	Go to Step 6
6	Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Is the replacement complete?	--	Go to Powertrain Control Module Diagnosis	--