DTC P0643 [WL-C, WE-C (Australian, European (L.H.D. U.K.) specs.)]

DTC P0643	Fuel pressure sensor and boost sensor 5 V circuit high input
DETECTION CONDITION	• The PCM monitors the fuel pressure sensor and boost sensor 5 V circuit. If the fuel pressure sensor and boost sensor power voltage is higher than 4.9 V, the PCM determines that there is a fuel pressure sensor and boost sensor 5 V circuit malfunction.
POSSIBLE CAUSE	• Short to power supply between boost sensor connector terminal C and PCM terminal 133 • Short to power supply between fuel sensor connector terminal C and PCM terminal 109 • Open circuit in wiring harness between boost sensor connector terminal C and PCM terminal 133 • Open circuit in wiring harness between fuel sensor connector terminal C and PCM terminal 109 • Boost sensor malfunction • Fuel pressure sensor malfunction • PCM malfunction

DTC P0643

Fuel pressure sensor and boost sensor 5 V circuit high input

DETECTION CONDITION

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

POSSIBLE CAUSE

• Short to power supply between boost sensor connector terminal C and PCM terminal 133

• Short to power supply between fuel sensor connector terminal C and PCM terminal 109

• Open circuit in wiring harness between boost sensor connector terminal C and PCM terminal 133

• Open circuit in wiring harness between fuel sensor connector 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	CLASSIFY BOOST SENSOR/IAT SENSOR NO.1 OR FUEL PRESSURE SENSOR RELATED MALFUNCTION • Turn the engine switch to the ON position (Engine off). • Measure the voltage between the boost sensor/IAT sensor No.1 connector terminal C and body ground. • Is the voltage 5 V constant voltage?	Yes	Go to step 14
No	If the voltage is 1.0 V or less, go to the next step. If the voltage is 5.1 V or more, go to Step 10.
5	INSPECT POOR CONNECTION OF BOOST SENSOR/IAT SENSOR NO.1 CONNECTOR • Turn the engine switch off. • Disconnect the boost sensor/IAT sensor No.1 connector. • Inspect for poor connection (damaged, pulled-out terminals, corrosion, etc.). • Is there a malfunction?	Yes	Repair or replace the terminals, then go to Step 24.
No	Go to the next step.
6	CLASSIFY BOOST SENSOR/IAT SENSOR NO.1 OR HARNESS RELATED MALFUNCTION • Disconnect the boost sensor/IAT sensor No.1 connector. • Turn the engine switch to the ON position (Engine off). • Measure the voltage between the boost sensor/IAT sensor No.1 connector terminal C and body ground. • Is the voltage 5 V constant voltage?	Yes	Go to the next step.
No	Go to step 8
7	INSPECT BOOST SENSOR/IAT SENSOR NO.1 • Inspect the boost sensor/IAT sensor No.1. (See BOOST SENSOR INSPECTION [WL-C, WE-C].) • Is there any malfunction?	Yes	Replace the boost sensor, then go to Step 24.
No	Go to Step 24.
8	INSPECT PCM CONNECTOR FOR POOR CONNECTION • Turn the engine switch off. • Disconnect the PCM connector. • Inspect for poor connection (damaged, pulled-out terminals, corrosion, etc.). • Is there a malfunction?	Yes	Repair or replace the pins, then go to Step 24.
No	Go to the next step.
9	INSPECT BOOST SENSOR/IAT SENSOR NO.1 POWER CIRCUIT FOR OPEN • Turn the engine switch off. • Inspect for continuity between the boost sensor/IAT sensor No.1 connector terminal C and PCM terminal 133 • Is there continuity?	Yes	Go to Step 24.
No	Repair or replace the wiring harness for an open, go to Step 24.
10	INSPECT POOR CONNECTION OF BOOST SENSOR/IAT SENSOR NO.1 CONNECTOR • Turn the engine switch off. • Disconnect the boost sensor/IAT sensor No.1 connector. • Inspect for poor connection (damaged, pulled-out terminals, corrosion, etc.). • Is there a malfunction?	Yes	Repair or replace the terminals, then go to Step 24.
No	Go to the next step.
11	CLASSIFY BOOST SENSOR/IAT SENSOR NO.1 OR HARNESS RELATED MALFUNCTION • Disconnect the boost sensor/IAT sensor No.1 connector. • Turn the engine switch to the ON position (Engine off). • Measure the voltage between the boost sensor/IAT sensor No.1 connector terminal C and body ground. • Is the voltage 5.1 V or more?	Yes	Go to the Step 13.
No	Go to the next step.
12	INSPECT BOOST SENSOR/IAT SENSOR NO.1 • Inspect the boost sensor/IAT sensor No.1. (See BOOST SENSOR INSPECTION [WL-C, WE-C].) • Is there any malfunction?	Yes	Replace the boost sensor, then go to Step 24.
No	Go to Step 24.
13	INSPECT PCM CONNECTOR FOR POOR CONNECTION • Turn the engine switch off. • Disconnect the PCM connector. • Inspect for poor connection (damaged, pulled-out terminals, corrosion, etc.). • Is there a malfunction?	Yes	Repair or replace the pins, then go to Step 24.
No	Repair or replace the wiring harness for a short to power, go to the Step 24.
14	CLASSIFY FUEL PRESSURE SENSOR OPEN CIRCUIT OR SHORT CIRCUIT RELATED MALFUNCTION • Turn the engine switch to the ON position (Engine off). • Measure the voltage between the fuel pressure sensor connector terminal C and body ground. • Is the voltage 5 V constant voltage?	Yes	Go to step 24
No	If the voltage is 1.0 V or less, go to the next step. If the voltage is 5.1 V or more, go to Step 20.
15	INSPECT POOR CONNECTION OF FUEL PRESSURE SENSOR CONNECTOR • Turn the engine switch off. • Disconnect the fuel pressure sensor connector. • Inspect for poor connection (damaged, pulled-out terminals, corrosion, etc.). • Is there a malfunction?	Yes	Repair or replace the terminals, then go to Step 24.
No	Go to the next step.
16	CLASSIFY FUEL PRESSURE SENSOR OR HARNESS RELATED MALFUNCTION • Disconnect the fuel pressure sensor connector. • Turn the engine switch to the ON position (Engine off). • Measure the voltage between the fuel pressure sensor connector terminal C and body ground. • Is the voltage 5 V constant voltage?	Yes	Go to the next step.
No	Go to step 18
17	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 fuel pressure sensor, then go to Step 24.
No	Go to Step 24.
18	INSPECT PCM CONNECTOR FOR POOR CONNECTION • Turn the engine switch off. • Disconnect the PCM connector. • Inspect for poor connection (damaged, pulled-out terminals, corrosion, etc.). • Is there a malfunction?	Yes	Repair or replace the pins, then go to Step 24.
No	Go to the next step.
19	INSPECT FUEL PRESSURE SENSOR POWER CIRCUIT FOR OPEN • Turn the engine switch off. • Inspect for continuity between the fuel pressure sensor connector terminal C and PCM terminal 109 • Is there continuity?	Yes	Go to Step 24.
No	Repair or replace the wiring harness for an open, go to Step 24.
20	INSPECT POOR CONNECTION OF FUEL PRESSURE SENSOR CONNECTOR • Turn the engine switch off. • Disconnect the fuel pressure sensor connector. • Inspect for poor connection (damaged, pulled-out terminals, corrosion, etc.). • Is there a malfunction?	Yes	Repair or replace the terminals, then go to Step 24.
No	Go to the next step.
21	CLASSIFY FUEL PRESSURE SENSOR OR HARNESS RELATED MALFUNCTION • Disconnect the fuel pressure sensor connector. • Turn the engine switch to the ON position (Engine off). • Measure the voltage between the fuel pressure sensor connector terminal C and body ground. • Is the voltage 5.1 V or more?	Yes	Go to the Step 23.
No	Go to the next step.
22	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 fuel pressure sensor, then go to Step 24.
No	Go to Step 24.
23	INSPECT PCM CONNECTOR FOR POOR CONNECTION • Turn the engine switch off. • Disconnect the PCM connector. • Inspect for poor connection (damaged, pulled-out terminals, corrosion, etc.). • Is there a malfunction?	Yes	Repair or replace the pins, then go to the next step.
No	Repair or replace the wiring harness for a short to power, go to the next step.
24	VERIFY TROUBLESHOOTING OF DTC P0643 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].) (See PCM REMOVAL/INSTALLATION (U.K. Specs.) [WL-C, WE-C].)
No	Go to the next step.
25	VERIFY AFTER REPAIR PROCEDURE • Perform the “After Repair Procedure“. (See AFTER REPAIR PROCEDURE [WL-C, WE-C (Australian, European (L.H.D. U.K.) specs.)].) • Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [WL-C, WE-C (Australian, European (L.H.D. U.K.) specs.)].)
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].)

CLASSIFY BOOST SENSOR/IAT SENSOR NO.1 OR FUEL PRESSURE SENSOR RELATED MALFUNCTION

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

• Measure the voltage between the boost sensor/IAT sensor No.1 connector terminal C and body ground.

• Is the voltage 5 V constant voltage?

Yes

Go to step 14

If the voltage is 1.0 V or less, go to the next step.

If the voltage is 5.1 V or more, go to Step 10.

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

• Turn the engine switch off.

• Disconnect the boost sensor/IAT sensor No.1 connector.

• Inspect for poor connection

(damaged, pulled-out terminals, corrosion, etc.).

• Is there a malfunction?

Yes

Repair or replace the terminals, then go to Step 24.

Go to the next step.

CLASSIFY BOOST SENSOR/IAT SENSOR NO.1 OR HARNESS RELATED MALFUNCTION

• Disconnect the boost sensor/IAT sensor No.1 connector.

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

• Measure the voltage between the boost sensor/IAT sensor No.1 connector terminal C and body ground.

• Is the voltage 5 V constant voltage?

Yes

Go to the next step.

Go to step 8

INSPECT BOOST SENSOR/IAT SENSOR NO.1

• Inspect the boost sensor/IAT sensor No.1.

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

• Is there any malfunction?

Yes

Replace the boost sensor, then go to Step 24.

Go to Step 24.

INSPECT PCM CONNECTOR FOR POOR CONNECTION

• Turn the engine switch off.

• Disconnect the PCM connector.

• Inspect for poor connection

(damaged, pulled-out terminals, corrosion, etc.).

• Is there a malfunction?

Yes

Repair or replace the pins, then go to Step 24.

Go to the next step.

INSPECT BOOST SENSOR/IAT SENSOR NO.1 POWER CIRCUIT FOR OPEN

• Turn the engine switch off.

• Inspect for continuity between the boost sensor/IAT sensor No.1 connector terminal C and PCM terminal 133

• Is there continuity?

Yes

Go to Step 24.

Repair or replace the wiring harness for an open, go to Step 24.

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

• Turn the engine switch off.

• Disconnect the boost sensor/IAT sensor No.1 connector.

• Inspect for poor connection

(damaged, pulled-out terminals, corrosion, etc.).

• Is there a malfunction?

Yes

Repair or replace the terminals, then go to Step 24.

Go to the next step.

CLASSIFY BOOST SENSOR/IAT SENSOR NO.1 OR HARNESS RELATED MALFUNCTION

• Disconnect the boost sensor/IAT sensor No.1 connector.

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

• Measure the voltage between the boost sensor/IAT sensor No.1 connector terminal C and body ground.

• Is the voltage 5.1 V or more?

Yes

Go to the Step 13.

Go to the next step.

INSPECT BOOST SENSOR/IAT SENSOR NO.1

• Inspect the boost sensor/IAT sensor No.1.

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

• Is there any malfunction?

Yes

Replace the boost sensor, then go to Step 24.

Go to Step 24.

INSPECT PCM CONNECTOR FOR POOR CONNECTION

• Turn the engine switch off.

• Disconnect the PCM connector.

• Inspect for poor connection

(damaged, pulled-out terminals, corrosion, etc.).

• Is there a malfunction?

Yes

Repair or replace the pins, then go to Step 24.

Repair or replace the wiring harness for a short to power, go to the Step 24.

CLASSIFY FUEL PRESSURE SENSOR OPEN CIRCUIT OR SHORT CIRCUIT RELATED MALFUNCTION

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

• Measure the voltage between the fuel pressure sensor connector terminal C and body ground.

• Is the voltage 5 V constant voltage?

Yes

Go to step 24

If the voltage is 1.0 V or less, go to the next step.

If the voltage is 5.1 V or more, go to Step 20.

INSPECT POOR CONNECTION OF FUEL PRESSURE SENSOR CONNECTOR

• Turn the engine switch off.

• Disconnect the fuel pressure sensor connector.

• Inspect for poor connection

(damaged, pulled-out terminals, corrosion, etc.).

• Is there a malfunction?

Yes

Repair or replace the terminals, then go to Step 24.

Go to the next step.

CLASSIFY FUEL PRESSURE SENSOR OR HARNESS RELATED MALFUNCTION

• Disconnect the fuel pressure sensor connector.

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

• Measure the voltage between the fuel pressure sensor connector terminal C and body ground.

• Is the voltage 5 V constant voltage?

Yes

Go to the next step.

Go to step 18

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 fuel pressure sensor, then go to Step 24.

Go to Step 24.

INSPECT PCM CONNECTOR FOR POOR CONNECTION

• Turn the engine switch off.

• Disconnect the PCM connector.

• Inspect for poor connection

(damaged, pulled-out terminals, corrosion, etc.).

• Is there a malfunction?

Yes

Repair or replace the pins, then go to Step 24.

Go to the next step.

INSPECT FUEL PRESSURE SENSOR POWER CIRCUIT FOR OPEN

• Turn the engine switch off.

• Inspect for continuity between the fuel pressure sensor connector terminal C and PCM terminal 109

• Is there continuity?

Yes

Go to Step 24.

Repair or replace the wiring harness for an open, go to Step 24.

INSPECT POOR CONNECTION OF FUEL PRESSURE SENSOR CONNECTOR

• Turn the engine switch off.

• Disconnect the fuel pressure sensor connector.

• Inspect for poor connection

(damaged, pulled-out terminals, corrosion, etc.).

• Is there a malfunction?

Yes

Repair or replace the terminals, then go to Step 24.

Go to the next step.

CLASSIFY FUEL PRESSURE SENSOR OR HARNESS RELATED MALFUNCTION

• Disconnect the fuel pressure sensor connector.

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

• Measure the voltage between the fuel pressure sensor connector terminal C and body ground.

• Is the voltage 5.1 V or more?

Yes

Go to the Step 23.

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 fuel pressure sensor, then go to Step 24.

Go to Step 24.

INSPECT PCM CONNECTOR FOR POOR CONNECTION

• Turn the engine switch off.

• Disconnect the PCM connector.

• Inspect for poor connection

(damaged, pulled-out terminals, corrosion, etc.).

• Is there a malfunction?

Yes

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

Repair or replace the wiring harness for a short to power, go to the next step.

VERIFY TROUBLESHOOTING OF DTC P0643 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].)

(See PCM REMOVAL/INSTALLATION (U.K. Specs.) [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 (Australian, European (L.H.D. U.K.) specs.)].)

• Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [WL-C, WE-C (Australian, European (L.H.D. U.K.) specs.)].)

DTC troubleshooting completed.