
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.
If system voltage is
below 11V, PCM sets P0562. MIL(Malfunction Indication Lamp) turns on when
the malfunction lasts till consecutive 2 driving cycle.
Item
|
Detecting
Condition
|
Possible cause
|
DTC
Strategy
|
|
|
Enable
Conditions
|
•
|
11V ≤ Battery voltage ≤
16V | |
Threshold
value
|
|
Diagnosis
Time
|
|
MIL On
Condition
|
|
Coil
Resistance
|
70Ω ~
120Ω
|

1. |
Check DTC Status
(1) |
Connect scantool to Data Link
Connector(DLC). |
(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.
|
|
■ Check voltage
2. |
Disconnect the main
relay. |
4. |
Measure the voltage between power supply
terminals of main relay harness connector and chassis
ground.
|
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
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
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.
|
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
2. |
Disconnect main relay and PCM
connector. |
3. |
Measure the resistance between control
terminal of main relay harness connector and chasses
ground.
|
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
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.
|
|
■ Check Generator circuit
2. |
Disconnect Generator
connector. |
4. |
Measure the voltage between lamp terminal of
Generator and chassis gound. |
5. |
Measure the voltage between FR terminal of
Generator and chassis gound.
|
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.
|
|
■ Check Main relay
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.
|
|