P0563 System Voltage High - Automotive Repair Guides & Equipment

COMPONENT LOCATION

GENERAL DESCRIPTION

The ECM monitors battery voltage while the engine is running. The ECM looks at voltage fed to the ECM from the Main Relay.

DTC DESCRIPTION

During engine running, if system voltage is above 16V, ECM sets P0563.

DTC DETECTING CONDITION

Item

Detecting Condition

Possible cause

DTC Strategy

Voltage too high

1.	Poor connection

2.	Short in circuit

3.	Faulty charging system

4.	Faulty main relay

5.	Faulty ECM

Enable Conditions

Engine works

Threshold value

System voltage > 16V

Diagnosis Time

Continuous

MIL On Condition

2 driving cycles

SPECIFICATION

Coil Resistance

70Ω ~ 120Ω

DIAGNOSTIC CIRCUIT DIAGRAM

SIGNAL WAVEFORM & DATA

Fig.1) Normal waveforms of COM, FR terminal of alternator at idle.

Fig.2) Normal waveforms of COM, FR terminal of alternator under high electronic load condition.

MONITOR GDS DATA

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

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.

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 ECM’s connector or was repaired and ECM memory was not cleared. Thoroughly check connectors for looseness, poor connection, ending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary

TERMINAL AND CONNECTOR INSPECTION

1.	Many malfunctions in the electrical system are caused by poor harness and terminals. 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

1.	IG “OFF” and disconnect Cruise switch connector.

IG “ON”

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

Approx. B+

Is the measured voltage within specification ?

	▶ Go to “Check short in harness” procedure.
	▶ Repair open or short to ground in 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 ECM harness terminal and chassis ground.

Approx. B+

Is the measured voltage within specification ?

	▶ Go to “System Inspection” procedure.
	▶ Repair short in power harness

SYSTEM INSPECTION

■ Check Generator circuit

1.	Engine starts.

2.	Maintain ENG RPM 2,500RPM over 2 minutes.

Measure voltage between the battery terminal(+) and the battery terminal(-).

Approx. 12.5 ~ 14.7V

Is the measured voltage within specification?

	▶ Go to “Component Inspection” procedure.
	▶ Check that the tension of drive belt, ENG RPM, fuse, terminal of battery, all terminals of generator are in good condition and Check for damaged harness and poor connection between generator and battery. If OK repair or replace generator

COMPONENT INSPECTION

■ Check Main relay

1.	IG “OFF” and disconnect main relay.

2.	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 ECM terminals of main relay.(Measurement “B”)

Specification :

Terminal	Continuity
Battery power supply – Power supply to ECM	NO
Battery power supply – Main relay control	YES(Approx. 70Ω ~ 120Ω)

Is the measured resistance within specification ?

▶ Substitute with a known – good ECM and check for proper operation. If the problem is corrected, replace ECM and go to “Verification of Vehicle Repair” procedure.

There is a memory reset function on GDS that can erase optional parts automatically detected and memorized by ECM. Before or after testing ECM on the vehicle, use this function to reuse the ECM on the others.

▶ Substitute with a known – good Relay and check for proper operation. If the problem is corrected, replace Relay

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