P1728

DTC P1728 EMC OPEN/SHORTED TO BATTERY





COMPONENT LOCATION

GENERAL DESCRIPTION
4WD ECM control EMC (Electric Magnet Clutch) by current and EMC distributes torque properly by using slip of multi-clutch.

DTC DESCRIPTION
As related with EMC, this trouble code will set in case EMC output harness is open or shorted to battery.





DTC DETECTING CONDITION





SCHEMATIC DIAGRAM





WAVEFORM INSPECTION

TERMINAL & CONNECTOR INSPECTION
1. Many malfunctions in the electrical system may be caused from poor harness and terminals. These faults can 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?
YES Repair as necessary and go to "Verification of Vehicle Repair" procedure.
NO Go to the next procedure.

SIGNAL CIRCUIT INSPECTION
1. EMC Signal Inspection
1) IG KEY ON, ENG IDLE
2) EMC connector: Connect.
3) Monitor signal waveform between terminal 1 of F43 harness connector and chassis ground.
4) Shift to N Range.
Specification: refer to "Waveform Inspection".
Is EMC Signal display near the specified value?
YES This may caused by intermittent fault. Verify data changeability by shaking the harness.
NO Keep 0V continuously.
^ Inspect open or short in EMC output line.
^ Check for 4WD ECM and replace it as necessary. Keep B+ continuously
^ Inspect open or short in EMC component inspection.
2. EMC output line open inspection
1) IG KEY OFF, ENG OFF
2) Electric Magnet Valve Clutch connector and 4WD ECM connector: Disconnect.





3) Measure resistance between terminal 1 of Electric Magnet Valve Clutch harness connector and terminal 26 of 4WD ECM harness connector.
Specification: Approximately 0 ohms
Is resistance display near the specified value?
YES Proceed next inspection procedure.
NO Repair open circuit of EMC output harness.
If problem is solved, go to the "Verification of Vehicle Repair".
3. EMC ground line open inspection
1) IG KEY OFF, ENG OFF
2) Electric Magnet Valve Clutch connector and 4WD ECM connector: Disconnect.





3) Measure resistance between terminal 2 of Electric Magnet Valve Clutch harness connector and terminal 13 of 4WD ECM harness connector M79.
Specification: Approximately 0 ohms
Is resistance display near the specified value?
YES Go to "Component inspection" procedure.
NO Repair open circuit of EMC ground harness.
If problem is solved, go to the "Verification of Vehicle Repair".

GROUND CIRCUIT INSPECTION
1. EMC output line short to ground inspection
1) IG KEY OFF, ENG OFF
2) Electric Magnet Valve Clutch connector: Disconnect.





3) Measure resistance between terminal 1 of Electric Magnet Valve Clutch harness connector and chassis ground.
Specification: Approximately 0 ohms
Is resistance display near the specified value?
YES Proceed next inspection procedure.
NO Repair ground to short circuit of EMC output harness.
If problem is solved, go to the "Verification of Vehicle Repair".

COMPONENT INSPECTION
1. IG KEY: OFF, Engine: OFF
2. Electric Magnet Valve Clutch connector: Disconnect.





3. Measure resistance between 1 & 2.
Specification: Approximately 1.8 - 2.2 ohms

NOTE: The above value is just for reference. The data from vehicle may differ from it according as various vehicle condition. This inspection is for checking open or short of EMC coil.

Is resistance display near the specified value?
YES Replace with normal 4WD ECM temporarily and check if vehicle run normally. If trouble is disappeared, replace 4WD ECM.
If problem is solved, go to the "Verification of Vehicle Repair".
NO Replace EMC coil.

VERIFICATION OF VEHICLE REPAIR
1. IG KEY ON, ENG ON
2. Electric Magnet Valve Clutch connector and 4WD ECM connector Disconnect.
3. Shift to N Range.
4. Check EMC output signal and verify the malfunction.
Does the scan tool display any DTC relevant to EMC signal?
YES Go to the applicable troubleshooting procedure.
NO System OK.