Fuel System > Engine Control System > P0563 System Voltage High

Commponent Location

General Description

The PCM provides ground to one side of the coil of the main relay and the other side is connected to the battery. The PCM monitors battery voltage and the voltage after the main relay.

DTC Description

If system voltage is above 16V, PCM sets P0563. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till consecutive 2 driving cycle.

DTC Detecting Condition

Item

Detecting Condition

Possible cause

DTC Strategy

•	Voltage too high

•	Poor connection

•	Short in circuit

•	Faulty charging system

•	Faulty main relay

•	Faulty PCM

Enable Conditions

•	Engine running

Threshold value

•	System voltage >16V

Diagnosis Time

•	Continuous

MIL On Condition

•	2 driving cycles

Specification

Coil Resistance

70Ω ~ 120Ω

Schematic Diagram

Monitor DTC Status

Check DTC Status

(1)	Connect scantool to Data Link Connector(DLC).

(2)

IG "ON".

(3)	Select "DTC" button, and then Press "DTC Status" to check DTC's information from the DTCs menu.

(4)	Read "DTC Status" parameter.

(5)

Is parameter displayed "Present fault"?

	▶ Go to "Terminal and connector inspection" procedure.
	▶ Fault is intermittent caused by poor contact in the sensor's and/or PCM's connector or was repaired and PCM memory was not cleared. Thoroughly check connectors for looseness, poor connection, ending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.

Terminal And Connector Inspection

1.	Many malfunctions in the electrical system are caused by poor harness and terminal condition. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.

2.	Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.

Has a problem been found?

	▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure
	▶ Go to " Power Circuit Inspection " procedure.

Power Circuit Inspection

■ Check voltage

IG "OFF".

2.	Disconnect the main relay.

3.	IG "ON" and ENG "OFF"

Measure the voltage between power supply terminals of main relay harness connector and chassis ground.

Specification : B+

Is the measured voltage within specification ?

	▶ Go to "Check short in harness" procedure.
	▶ Repair short in power harness and go to "Verification of Vehicle Repair" procedure.

■ Check short in harness

IG "ON".

Measure the voltage between main relay 'ON' power terminals of PCM harness terminal and chassis ground.

Specification : B+

Is the measured voltage within specification ?

	▶ Go to "System Inspection" procedure.
	▶ Repair short in power harness and go to "Verification of Vehicle Repair" procedure.

System Inspection

■ Check Generator circuit

IG "OFF".

2.	Disconnect Generator connector.

3.	IG "ON" and ENG "OFF"

4.	Measure the voltage between lamp terminal of Generator and chassis gound.

Measure the voltage between FR terminal of Generator and chassis gound.

Specification : B+

Is the measured voltage within specification?

	▶ Go to "Component Inspection" procedure.
	▶ Repair short in Sensing circuit or MIL circuit and go to "Verification of Vehicle Repair" procedure.

Component Inspection

■ Check Main relay

IG "OFF".

2.	Disconnect the main relay.

3.	Measure the resistance between battery power supply and control terminals of main relay.(Measurement "A")

Measure the resistance between battery power supply and power supply to PCM terminals of main relay.(Measurement "B")

Specification : 70 ~ 120Ω

Terminal	Power approval
Battery power supply - Power supply to PCM	NO
Battery power supply - Main relay control	YES (Approx. 70Ω ~ 120Ω)

Is the measured resistance within specification ?

	▶ Go to "Check Generator" procedure.
	▶ Substitute with a known - good Main relay and check for proper operation. If the problem is corrected, replace Main relay and go to "Verification of Vehicle Repair" procedure.

■ Check Generator

IG "OFF".

2.	Check the tension of the belt.

3.	Check Battery terminal and Generator B+ terminal for looseness, corrosion or damage.

4.	Engine "ON".

5.	Operate electric equipments (Head lamp, Hot wire, etc).

Accelerate engine to 2000 RPM and measure the battery voltage.

Specification : Approx. 12.5V ~ 14.5V

Is the measured voltage within specification ?

	▶ Substitute with a known - good PCM and check for proper operation. If the problem is corrected, replace PCM and go to "Verification of Vehicle Repair" procedure.
	▶ Substitute with a known - good Generator and check for proper operation. If the problem is corrected, replace Generator and go to "Verification of Vehicle Repair" procedure.

There is a memory reset function on scantool that can erase optional parts automatically detected and memorized by PCM. After testing PCM on the vehicle, use this function to reuse the PCM on the others.

Verification Of Vehicle Repair

After a repair, it is essential to verify that the fault has been corrected.

1.	Connect scantool and select "DTC" button.

2.	Press "DTC Status" button and confirm that "DTC Readiness Flag" indicates "Completed". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions

3.	Read "DTC Status" parameter

Is parameter displayed "History(Not Present) fault"?

	▶ System performing to specification at this time. Clear the DTC
	▶ Go to the applicable troubleshooting procedure.