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DTC P0642:00 [PCM (SKYACTIV-D)]

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Outline

System malfunction location	Constant voltage power supply circuit low input
Detection condition	•  When the following condition is met, the output voltage of the constant voltage (5 V) power supply terminal is less than 2.36 V for a continuous 0.5 s. ―  Battery positive voltage: 8—16 V
Fail-safe	•  PCM restricts engine torque. •  Limits the maximum engine speed. •  Inhibits the DENOx/DESOx control. •  Inhibits the diesel particulate filter regeneration control. •  Inhibits the EGR control. •  PCM restricts engine-transaxle integration control. (ATX) •  Inhibits engine-stop by operating the i-stop function.
Possible cause	•  APP sensor connector or terminal malfunction •  CKP sensor connector or terminal malfunction •  MAP sensor connector or terminal malfunction •  Engine oil temperature/engine oil pressure sensor connector or terminal malfunction •  MAF/IAT sensor No.1 connector or terminal malfunction •  Power brake unit vacuum sensor connector or terminal malfunction •  Clutch stroke sensor connector or terminal malfunction (MTX) •  Refrigerant pressure sensor No.1 connector or terminal malfunction •  Refrigerant pressure sensor No.2 connector or terminal malfunction •  Fuel pressure sensor (integrated with fuel injector No.1) connector or terminal malfunction •  Fuel pressure sensor (integrated with fuel injector No.4) connector or terminal malfunction •  Actuator position sensor (turbocharger) connector or terminal malfunction •  LP-EGR control valve/LP-EGR control valve position sensor connector or terminal malfunction •  Short to ground in APP sensor power supply circuit •  Short to ground in CKP sensor power supply circuit •  Short to ground in MAP sensor power supply circuit •  Short to ground in engine oil temperature/engine oil pressure sensor power supply circuit •  Short to ground in MAF/IAT sensor No.1 power supply circuit •  Short to ground in Power brake unit vacuum sensor power supply circuit •  Short to ground in Clutch stroke sensor power supply circuit •  Short to ground in Refrigerant pressure sensor No.1 power supply circuit •  Short to ground in Refrigerant pressure sensor No.2 power supply circuit •  Short to ground in Fuel pressure sensor (integrated with fuel injector No.1) power supply circuit •  Short to ground in Fuel pressure sensor (integrated with fuel injector No.4) power supply circuit •  Short to ground in Actuator position sensor (turbocharger) power supply circuit •  Short to ground in LP-EGR control valve power supply circuit •  PCM connector or terminal malfunction •  PCM malfunction

Diagnostic Procedure

Caution

•  If a hand or tool touches the fuel injector terminal, the fuel injector might be damaged. To prevent this, do not touch the terminal.

•  If high-voltage generating parts or components and electronic devices come near a fuel injector, the fuel injector could be damaged. To prevent damage to a fuel injector, always keep high-voltage generating parts or components and electronic devices away from it.

Step	Inspection	Results	Action
1	RECORD VEHICLE STATUS WHEN DTC WAS DETECTED TO UTILIZE WITH REPEATABILITY VERIFICATION •  Record the freeze frame data/snapshot data. Note •  Recording can be facilitated using the screen capture function of the PC.	—	Go to the next step.
2	VERIFY RELATED REPAIR INFORMATION OR SERVICE INFORMATION AVAILABILITY •  Verify related Service Bulletins, on-line repair information, or Service Information availability. •  Is any related Information available?	Yes	Perform repair or diagnosis according to the available information. •  If the vehicle is not repaired, go to the next step.
		No	Go to the next step.
3	INSPECT FOR OTHER RELATED DTCs •  Perform the DTC inspection for the PCM. (See DTC INSPECTION.) •  Are any other DTCs displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting. (See DTC TABLE [PCM (SKYACTIV-D)].)
		No	Go to the next step.
4	INSPECT PCM CONNECTOR FOR MALFUNCTION •  Inspect the applicable connector and terminal. (See CONNECTOR INSPECTION.) •  Are the connector and terminal normal?	Yes	Go to the next step.
		No	Repair or replace the malfunctioning location and perform the repair completion verification.
5	INSPECT APP SENSOR CONNECTOR FOR MALFUNCTION •  Inspect the applicable connector and terminal. (See CONNECTOR INSPECTION.) •  Are the connector and terminal normal?	Yes	Go to the next step.
		No	Repair or replace the malfunctioning location and perform the repair completion verification.
6	INSPECT CKP SENSOR CONNECTOR FOR MALFUNCTION •  Inspect the applicable connector and terminal. (See CONNECTOR INSPECTION.) •  Are the connector and terminal normal?	Yes	Go to the next step.
		No	Repair or replace the malfunctioning location and perform the repair completion verification.
7	INSPECT MAP SENSOR CONNECTOR FOR MALFUNCTION •  Inspect the applicable connector and terminal. (See CONNECTOR INSPECTION.) •  Are the connector and terminal normal?	Yes	Go to the next step.
		No	Repair or replace the malfunctioning location and perform the repair completion verification.
8	INSPECT ENGINE OIL TEMPERATURE/ENGINE OIL PRESSURE SENSOR CONNECTOR FOR MALFUNCTION •  Inspect the applicable connector and terminal. (See CONNECTOR INSPECTION.) •  Are the connector and terminal normal?	Yes	Go to the next step.
		No	Repair or replace the malfunctioning location and perform the repair completion verification.
9	INSPECT MAF/IAT SENSOR No.1 CONNECTOR FOR MALFUNCTION •  Inspect the applicable connector and terminal. (See CONNECTOR INSPECTION.) •  Are the connector and terminal normal?	Yes	Go to the next step.
		No	Repair or replace the malfunctioning location and perform the repair completion verification.
10	INSPECT POWER BRAKE UNIT VACUUM SENSOR CONNECTOR FOR MALFUNCTION •  Inspect the applicable connector and terminal. (See CONNECTOR INSPECTION.) •  Are the connector and terminal normal?	Yes	MTX •  Go to the next step. ATX •  Go to Step 12.
		No	Repair or replace the malfunctioning location and perform the repair completion verification.
11	INSPECT CLUTCH STROKE SENSOR CONNECTOR FOR MALFUNCTION •  Inspect the applicable connector and terminal. (See CONNECTOR INSPECTION.) •  Are the connector and terminal normal?	Yes	Go to the next step.
		No	Repair or replace the malfunctioning location and perform the repair completion verification.
12	INSPECT REFRIGERANT PRESSURE SENSOR No.1 AND No.2 CONNECTOR FOR MALFUNCTION •  Inspect the applicable connector and terminal. (See CONNECTOR INSPECTION.) •  Are the connector and terminal normal?	Yes	Go to the next step.
		No	Repair or replace the malfunctioning location and perform the repair completion verification.
13	INSPECT FUEL PRESSURE SENSOR (INTEGRATED WITH FUEL INJECTOR No.1) CONNECTOR FOR MALFUNCTION •  Inspect the applicable connector and terminal. (See CONNECTOR INSPECTION.) •  Are the connector and terminal normal?	Yes	Go to the next step.
		No	Repair or replace the malfunctioning location and perform the repair completion verification.
14	INSPECT FUEL PRESSURE SENSOR (INTEGRATED WITH FUEL INJECTOR No.4) CONNECTOR FOR MALFUNCTION •  Inspect the applicable connector and terminal. (See CONNECTOR INSPECTION.) •  Are the connector and terminal normal?	Yes	Go to the next step.
		No	Repair or replace the malfunctioning location and perform the repair completion verification.
15	INSPECT VARIABLE TURBINE GEOMETRY TURBOCHARGER ACTUATOR POSITION SENSOR CONNECTOR FOR MALFUNCTION •  Inspect the applicable connector and terminal. (See CONNECTOR INSPECTION.) •  Are the connector and terminal normal?	Yes	Go to the next step.
		No	Repair or replace the malfunctioning location and perform the repair completion verification.
16	INSPECT LP-EGR CONTROL VALVE/LP-EGR CONTROL VALVE POSITION SENSOR CONNECTOR FOR MALFUNCTION •  Inspect the applicable connector and terminal. (See CONNECTOR INSPECTION.) •  Are the connector and terminal normal?	Yes	Go to the next step.
		No	Repair or replace the malfunctioning location and perform the repair completion verification.
17	INSPECT EACH POWER SUPPLY CIRCUIT FOR SHORT TO GROUND •  Inspect the applicable circuit for a short to ground. (See CIRCUIT INSPECTION.) •  Is the circuit normal?	Yes	Go to the next step.
		No	Repair or replace the malfunctioning location and perform the repair completion verification.
Repair completion verification 1	VERIFY THAT VEHICLE IS REPAIRED •  Install/connect the part removed/disconnected during the troubleshooting procedure. •  Clear the DTC recorded in the memory. (See CLEARING DTC.) •  Replicate the vehicle conditions at the time the DTC was detected using the following procedure. ―  Switch the ignition ON (engine off) and wait for 30 s. •  Perform the DTC inspection for the PCM. (See DTC INSPECTION.) •  Is the same Pending DTC present?	Yes	Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error. (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(E)].) If the CAN communication is normal, perform the diagnosis from Step 1. •  If the malfunction recurs, replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [SKYACTIV-D 1.8].)
		No	Go to the next step.
Repair completion verification 2	VERIFY IF OTHER DTCs DISPLAYED •  Perform the DTC inspection. (See DTC INSPECTION.) •  Are any other DTCs displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting.
		No	DTC troubleshooting completed.