DTC P0642:00 [SKYACTIV-D 2.2]

id0102s4315500

DTC P0642:00

Constant voltage power supply circuit low input
DETECTION CONDITION
•  When the following condition is met, the output voltage of the 5 V power supply terminal 4.868 V or less for a continuous 1 s:
MONITORING CONDITIONS
―  Battery voltage: 8—20 V
Diagnostic support note
•  This is a continuous monitor (CCM).
•  The check engine light illuminates if the PCM detects the above malfunction condition during the first drive cycle.
•  FREEZE FRAME DATA (Mode 2)/Snapshot data is available.
•  DTC is stored in the PCM memory.
FAIL-SAFE FUNCTION
•  Inhibits the EGR control.
•  Inhibits engine-stop by operating the i-stop function.
POSSIBLE CAUSE
•  APP sensor connector or terminals malfunction
•  CKP sensor connector or terminals malfunction
•  MAP sensor No.2 connector or terminals malfunction
•  Engine oil temperature sensor/engine oil pressure sensor connector or terminals malfunction
•  MAF sensor/IAT sensor No.1 connector or terminals malfunction
•  Regulating valve position sensor connector or terminals malfunction
•  Power brake unit vacuum sensor connector or terminals malfunction
•  Refrigerant pressure sensor connector or terminals malfunction
•  Short to ground in wiring harness between the following terminals:
―  APP sensor terminal A—PCM terminal 2AM
―  CKP sensor terminal A—PCM terminal 1J
―  MAP sensor No.2 terminal C—PCM terminal 1CN
―  Engine oil temperature sensor/engine oil pressure sensor terminal A—PCM terminal 1DN
―  MAF sensor/IAT sensor No.1 terminal D—PCM terminal 2AC
―  Regulating valve position sensor terminal C—PCM terminal 1BO
―  Power brake unit vacuum sensor terminal A—PCM terminal 2BB
―  Refrigerant pressure sensor terminal A—PCM terminal 2BB
•  PCM connector or terminals malfunction
•  PCM malfunction

Diagnostic Procedure

STEP

INSPECTION

ACTION
1
VERIFY FREEZE FRAME DATA (MODE 2)/SNAPSHOT DATA HAS BEEN RECORDED
•  Has the FREEZE FRAME DATA (Mode 2)/snapshot data been recorded?
Yes
Go to the next step.
No
Record the FREEZE FRAME DATA (Mode 2)/snapshot data on the repair order, then go to the next step.
2
VERIFY RELATED SERVICE INFORMATION AVAILABILITY
•  Verify related Service Information availability.
•  Is any related Service Information available?
Yes
Perform repair or diagnosis according to the available Service Information.
•  If the vehicle is not repaired, go to the next step.
No
Go to the next step.
3
VERIFY RELATED PENDING CODE AND/OR DTC
•  Switch the ignition off, then ON (engine off).
•  Perform the Pending Trouble Code Access Procedure and DTC Reading Procedure.
•  Are any other PENDING CODEs and/or DTCs present?
Yes
Go to the applicable PENDING CODE or DTC inspection.
(See DTC TABLE [SKYACTIV-D 2.2].)
No
Go to the next step.
4
INSPECT APP SENSOR CONNECTOR CONDITION
•  Switch the ignition off.
•  Disconnect the APP sensor connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the connector and/or terminals, then go to Step 14.
No
Go to the next step.
5
INSPECT CKP SENSOR CONNECTOR CONDITION
•  Disconnect the CKP sensor connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the connector and/or terminals, then go to Step 14.
No
Go to the next step.
6
INSPECT MAP SENSOR NO.2 CONNECTOR CONDITION
•  Disconnect the MAP sensor No.2 connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the connector and/or terminals, then go to Step 14.
No
Go to the next step.
7
INSPECT ENGINE OIL TEMPERATURE SENSOR/ENGINE OIL PRESSURE SENSOR CONNECTOR CONDITION
•  Disconnect the engine oil temperature sensor/engine oil pressure sensor connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the connector and/or terminals, then go to Step 14.
No
Go to the next step.
8
INSPECT MAF SENSOR/IAT SENSOR NO.1 CONNECTOR CONDITION
•  Disconnect the MAF sensor/IAT sensor No.1 connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the connector and/or terminals, then go to Step 14.
No
Go to the next step.
9
INSPECT REGULATING VALVE POSITION SENSOR CONNECTOR CONDITION
•  Disconnect the regulating valve position sensor connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the connector and/or terminals, then go to Step 14.
No
Go to the next step.
10
INSPECT POWER BRAKE UNIT VACUUM SENSOR CONNECTOR CONDITION
•  Disconnect the power brake unit vacuum sensor connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the connector and/or terminals, then go to Step 14.
No
Go to the next step.
11
INSPECT REFRIGERANT PRESSURE SENSOR CONNECTOR CONDITION
•  Disconnect the refrigerant pressure sensor connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the connector and/or terminals, then go to Step 14.
No
Go to the next step.
12
INSPECT EACH POWER SUPPLY CIRCUIT FOR SHORT TO GROUND
•  Verify that the APP sensor and CKP sensor and MAP sensor No.2 and engine oil temperature sensor/engine oil pressure sensor and MAF sensor/IAT sensor No.1 and regulating valve position sensor and power brake unit vacuum sensor and refrigerant pressure sensor connectors are disconnected.
•  Inspect for continuity between the following terminals (wiring harness-side) and body ground:
―  APP sensor terminal A
―  CKP sensor terminal A
―  MAP sensor No.2 terminal C
―  Engine oil temperature sensor/engine oil pressure sensor terminal A
―  MAF sensor/IAT sensor No.1 terminal D
―  Regulating valve position sensor terminal C
―  Power brake unit vacuum sensor terminal A
―  Refrigerant pressure sensor terminal A
•  Is there continuity?
Yes
If the short to ground circuit could be detected in the wiring harness:
•  Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:
―  APP sensor terminal A—PCM terminal 2AM
―  CKP sensor terminal A—PCM terminal 1J
―  MAP sensor No.2 terminal C—PCM terminal 1CN
―  Engine oil temperature sensor/engine oil pressure sensor terminal A—PCM terminal 1DN
―  MAF sensor/IAT sensor No.1 terminal D—PCM terminal 2AC
―  Regulating valve position sensor terminal C—PCM terminal 1BO
―  Power brake unit vacuum sensor terminal A—PCM terminal 2BB
―  Refrigerant pressure sensor terminal A—PCM terminal 2BB
If there is a common connector:
―  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.
―  Repair or replace the malfunctioning part.
If there is no common connector:
―  Repair or replace the wiring harness which has a short to ground.
If the short to ground circuit could not be detected in the wiring harness:
•  Replace the PCM (short to ground in the PCM internal circuit).
Go to Step 14.
No
Go to the next step.
13
INSPECT PCM CONNECTOR CONDITION
•  Disconnect the PCM connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the connector and/or terminals, then go to the next step.
No
Go to the next step.
14
VERIFY DTC TROUBLESHOOTING COMPLETED
•  Always reconnect all disconnected connectors.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Switch the ignition ON (engine off) and wait for 30 s or more.
•  Perform the DTC Reading Procedure.
•  Is the same DTC present?
Yes
Repeat the inspection from Step 1.
•  If the malfunction recurs, replace the PCM.
Go to the next step.
No
Go to the next step.
15
VERIFY AFTER REPAIR PROCEDURE
•  Perform the “AFTER REPAIR PROCEDURE”.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [SKYACTIV-D 2.2].)
No
DTC troubleshooting completed.