VERACRUZ(EN) >2009 > G 3.8 DOHC > Fuel System > Engine Control System>P0562 System Voltage Low  
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 below 11V, PCM sets P0562. 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 low
Poor connection
Open in power circuit
Faulty charging system
Faulty main relay
Faulty PCM
Enable Conditions
Engine running
11V ≤ Battery voltage ≤ 16V
Threshold value
System voltage< 11V
Diagnosis Time
Continuous
MIL On Condition
2 driving cycles

Specification
Coil Resistance
70Ω ~ 120Ω

Schematic Diagram

Monitor DTC Status
1.
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.
3.
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".
2.
Disconnect the main relay.
3.
IG "ON" and ENG "OFF"
4.
Measure the voltage between power supply terminals of main relay harness connector and chassis ground.

Specification : B+

5.
Is the measured voltage within specification ?

▶ Go to "Check open in harness" procedure.

▶ Check the fuse between battery and main relay.
▶ Repair Open or Short to ground in power circuit and go to "Verification of Vehicle Repair" procedure.

■ Check open in harness
1.
IG "OFF".
2.
Disconnect main relay and PCM connector.
3.
Measure the resistance between main relay 'ON' power terminal of main relay harness connector and main relay 'ON' power terminals of PCM harness connector.

Specification : Approx. below 1Ω

4.
Is the measured resistance within specification ?

▶ Go to "Check short in harness" procedure.

▶ Repair open in harness and go to "Verification of Vehicle Repair" procedure.

■ Check short in harness
1.
IG "OFF".
2.
Disconnect main relay and PCM connector.
3.
Measure the resistance between main relay 'ON' power terminal of main relay harness connector and chassis ground.

Specification : Infinite

4.
Is the measured resistance within specification ?

▶ Go to "Control Circuit Inspection" procedure.

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

Control Circuit Inspection
■ Check short in harness
1.
IG "OFF".
2.
Disconnect main relay and PCM connector.
3.
Measure the resistance between control terminal of main relay harness connector and chasses ground.

Specification : Infinite

4.
Is the measured resistance within specification ?

▶ Go to "Check open in harness" procedure.

▶ Repair short in control harness and go to "Verification of Vehicle Repair" procedure.

■ Check open in harness
1.
IG "OFF".
2.
Disconnect main relay and PCM connector.
3.
Measure the resistance between control terminal of main relay harness connector and main relay control terminal of PCM harness connector.

Specification : Approx. below 1Ω

4.
Is the measured resistance within specification ?

▶ Go to "System Inspection" procedure.

▶ Repair open in control harness and go to "Verification of Vehicle Repair" procedure.

System Inspection
■ Check Generator circuit
1.
IG "OFF".
2.
Disconnect Generator connector.
3.
IG "ON" and ENG "OFF"
4.
Measure the voltage between lamp terminal of Generator and chassis gound.
5.
Measure the voltage between FR terminal of Generator and chassis gound.

Specification : B+

6.
Is the measured voltage within specification?

▶ Go to "Component Inspection" procedure.

▶ In case terminal 2 : Repair MIL circuit, MIL resistor or Open in circuit and go to "Verification of Vehicle Repair" procedure.
▶ In case terminal 3 : Repair the fuse between battery and Ignition switch, the fuse between Ignition switch and alternator or Open in circuit and go to "Verification of Vehicle Repair" procedure.

Component Inspection
■ Check Main relay
1.
IG "OFF".
2.
Disconnect the main relay.
3.
Measure the resistance between battery power supply and control terminals of main relay.(Measurement "A")
4.
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)

5.
Is the measured resistance 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 Main relay and check for proper operation. If the problem is corrected, replace Main relay 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
4.
Is parameter displayed "History(Not Present) fault"?

▶ System performing to specification at this time. Clear the DTC

▶ Go to the applicable troubleshooting procedure.