DTC P0642 [WL-C, WE-C]

DTC P0642	Fuel pressure sensor and boost sensor 5 V circuit low input
DETECTION CONDITION	• The PCM monitors the fuel pressure sensor and the boost sensor 5 V circuit. If the fuel pressure sensor and boost sensor power voltage is lower than 4.9 V, the PCM determines that there is a fuel pressure sensor and boost sensor 5 V circuit malfunction.
POSSIBLE CAUSE	• Connector or terminal malfunction • Short to ground circuit between circuit in wiring between boost sensor terminal C and PCM terminal 133 • Short to ground circuit between circuit in wiring between fuel pressure sensor terminal C and PCM terminal 109 • Boost sensor malfunction • Fuel pressure sensor malfunction • PCM malfunction

DTC P0642

Fuel pressure sensor and boost sensor 5 V circuit low input

DETECTION CONDITION

• The PCM monitors the fuel pressure sensor and the boost sensor 5 V circuit. If the fuel pressure sensor and boost sensor power voltage is lower than 4.9 V, the PCM determines that there is a fuel pressure sensor and boost sensor 5 V circuit malfunction.

POSSIBLE CAUSE

• Connector or terminal malfunction

• Short to ground circuit between circuit in wiring between boost sensor terminal C and PCM terminal 133

• Short to ground circuit between circuit in wiring between fuel pressure sensor terminal C and PCM terminal 109

• Boost sensor malfunction

• Fuel pressure sensor malfunction

• PCM malfunction

STEP	INSPECTION	ACTION
1	VERIFY FREEZE FRAME DATA HAS BEEN RECORDED • Has the FREEZE FRAME DATA been recorded?	Yes	Go to the next step.
No	Record the FREEZE FRAME 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 CURRENT SIGNAL STATUS: IS CONCERN INTERMITTENT OR CONSTANT? • Connect the M-MDS to the DLC-2. • Clear the DTC from the PCM memory using the M-MDS. • Run the vehicle under the FREEZE FRAME DATA stored condition. • Is the same DTC present?	Yes	Go to the next step.
No	Intermittent concern exists. Perform the “INTERMITTENT CONCERNS TROUBLESHOOTING”. (See INTERMITTENT CONCERN TROUBLESHOOTING [WL-C, WE-C].)
4	INSPECT BOOST SENSOR/IAT SENSOR NO.1 CONNECTOR FOR POOR CONNECTION • Turn the engine switch off. • Disconnect the boost 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 terminal, then go to Step 11.
No	Go to the next step.
5	INSPECT FUEL PRESSURE SENSOR CONNECTOR FOR POOR CONNECTION • Turn the engine switch off. • Disconnect the fuel pressure sensor connector. • Inspect for poor connection (such as damaged/pulled-out pins, corrosion). • Is there any malfunction?	Yes	Repair or replace the terminal, then go to Step 11.
No	Go to the next step.
6	INSPECT BOOST SENSOR/IAT SENSOR NO.1 CIRCUIT FOR SHORT TO GROUND • Turn the engine switch off. • Inspect for continuity between the boost sensor terminal C (wiring harness-side) and body ground. • Is there continuity?	Yes	Repair or replace the wiring harness for a possible short to ground, then go to Step 11.
No	Go to the next step.
7	INSPECT FUEL PRESSURE SENSOR CIRCUIT FOR SHORT TO GROUND • Turn the engine switch off. • Inspect for continuity between the fuel pressure sensor terminal C (wiring harness-side) and body ground. • Is there continuity?	Yes	Repair or replace the wiring harness for a possible short to ground, then go to Step 11.
No	Go to the next step.
8	INSPECT BOOST SENSOR • Inspect the boost sensor. (See BOOST SENSOR INSPECTION [WL-C, WE-C].) • Is there any malfunction?	Yes	Replace the boost sensor/IAT sensor No.1, then go to Step 11.
No	Go to the next step.
9	INSPECT FUEL PRESSURE SENSOR • Inspect the fuel pressure sensor. (See FUEL PRESSURE SENSOR INSPECTION [WL-C, WE-C].) • Is there any malfunction?	Yes	Replace the common rail, then go to Step 11.
No	Go to the next step.
10	INSPECT PCM CONNECTOR FOR POOR CONNECTION • Turn the engine switch off. • Disconnect the PCM connector. • Inspect for poor connection (such as damaged/pulled-out pins, corrosion). • Is there any malfunction?	Yes	Repair or replace the terminal, then go to the next step.
No	Go to the next step.
11	VERIFY TROUBLESHOOTING OF DTC P0642 COMPLETED • Turn the engine switch off. • Make sure to reconnect all disconnected connectors. • Turn the engine switch to the ON position (Engine off). • Clear the DTC from the memory using the M-MDS. • Run the vehicle under the FREEZE FRAME DATA stored condition. • Is the same DTC present?	Yes	Replace PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [WL-C, WE-C].)
No	Go to the next step.
12	VERIFY AFTER REPAIR PROCEDURE • Perform the “After Repair Procedure“. (See AFTER REPAIR PROCEDURE [WL-C, WE-C].) • Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [WL-C, WE-C].)
No	DTC troubleshooting completed.

STEP

INSPECTION

ACTION

VERIFY FREEZE FRAME DATA HAS BEEN RECORDED

• Has the FREEZE FRAME DATA been recorded?

Yes

Go to the next step.

Record the FREEZE FRAME DATA on the repair order, then go to the next step.

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.

Go to the next step.

VERIFY CURRENT SIGNAL STATUS: IS CONCERN INTERMITTENT OR CONSTANT?

• Connect the M-MDS to the DLC-2.

• Clear the DTC from the PCM memory using the M-MDS.

• Run the vehicle under the FREEZE FRAME DATA stored condition.

• Is the same DTC present?

Yes

Go to the next step.

Intermittent concern exists.

Perform the “INTERMITTENT CONCERNS TROUBLESHOOTING”.

(See INTERMITTENT CONCERN TROUBLESHOOTING [WL-C, WE-C].)

INSPECT BOOST SENSOR/IAT SENSOR NO.1 CONNECTOR FOR POOR CONNECTION

• Turn the engine switch off.

• Disconnect the boost 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 terminal, then go to Step 11.

Go to the next step.

INSPECT FUEL PRESSURE SENSOR CONNECTOR FOR POOR CONNECTION

• Turn the engine switch off.

• Disconnect the fuel pressure sensor connector.

• Inspect for poor connection (such as damaged/pulled-out pins, corrosion).

• Is there any malfunction?

Yes

Repair or replace the terminal, then go to Step 11.

Go to the next step.

INSPECT BOOST SENSOR/IAT SENSOR NO.1 CIRCUIT FOR SHORT TO GROUND

• Turn the engine switch off.

• Inspect for continuity between the boost sensor terminal C (wiring harness-side) and body ground.

• Is there continuity?

Yes

Repair or replace the wiring harness for a possible short to ground, then go to Step 11.

Go to the next step.

INSPECT FUEL PRESSURE SENSOR CIRCUIT FOR SHORT TO GROUND

• Turn the engine switch off.

• Inspect for continuity between the fuel pressure sensor terminal C (wiring harness-side) and body ground.

• Is there continuity?

Yes

Repair or replace the wiring harness for a possible short to ground, then go to Step 11.

Go to the next step.

INSPECT BOOST SENSOR

• Inspect the boost sensor.

(See BOOST SENSOR INSPECTION [WL-C, WE-C].)

• Is there any malfunction?

Yes

Replace the boost sensor/IAT sensor No.1, then go to Step 11.

Go to the next step.

INSPECT FUEL PRESSURE SENSOR

• Inspect the fuel pressure sensor.

(See FUEL PRESSURE SENSOR INSPECTION [WL-C, WE-C].)

• Is there any malfunction?

Yes

Replace the common rail, then go to Step 11.

Go to the next step.

INSPECT PCM CONNECTOR FOR POOR CONNECTION

• Turn the engine switch off.

• Disconnect the PCM connector.

• Inspect for poor connection (such as damaged/pulled-out pins, corrosion).

• Is there any malfunction?

Yes

Repair or replace the terminal, then go to the next step.

Go to the next step.

VERIFY TROUBLESHOOTING OF DTC P0642 COMPLETED

• Turn the engine switch off.

• Make sure to reconnect all disconnected connectors.

• Turn the engine switch to the ON position (Engine off).

• Clear the DTC from the memory using the M-MDS.

• Run the vehicle under the FREEZE FRAME DATA stored condition.

• Is the same DTC present?

Yes

Replace PCM, then go to the next step.

(See PCM REMOVAL/INSTALLATION [WL-C, WE-C].)

Go to the next step.

VERIFY AFTER REPAIR PROCEDURE

• Perform the “After Repair Procedure“.

(See AFTER REPAIR PROCEDURE [WL-C, WE-C].)

• Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [WL-C, WE-C].)

DTC troubleshooting completed.