DTC P0642:00 [MZ-CD 1.6]

DTC P0642:00	Sensor reference circuit low input
DETECTION CONDITION	• The PCM monitors the sensor reference voltage from the EGR valve position sensor, intake shutter valve position sensor, wastegate valve actuator position sensor, MAP sensor and diesel particulate filter differential pressure sensor. If the power supply voltage for the EGR valve position sensor, intake shutter valve position sensor, wastegate valve actuator position sensor, MAP sensor, or diesel particulate filter differential pressure sensor is less than 4.74609 V the PCM determines that the sensor reference voltage circuit has a malfunction.
POSSIBLE CAUSE	• EGR valve position sensor connector or terminal malfunction • Intake shutter valve position sensor connector or terminal malfunction • Wastegate valve actuator position sensor connector or terminal malfunction • MAP sensor connector or terminal malfunction • Diesel particulate filter differential pressure sensor connector or terminal malfunction • Short to ground in wiring harness between EGR valve position sensor terminal E and PCM terminal 2AO • Short to ground in wiring harness between intake shutter valve position sensor terminal A and PCM terminal 2AO • Short to ground in wiring harness between wastegate valve actuator position sensor terminal B and PCM terminal 2AS • Short to ground in wiring harness between MAP sensor terminal C and PCM terminal 2AS • Short to ground in wiring harness between diesel particulate filter differential pressure sensor terminal A and PCM terminal 2AT • EGR valve position sensor malfunction • Intake shutter valve position sensor malfunction • Wastegate valve actuator position sensor malfunction • MAP sensor malfunction • Diesel particulate filter differential pressure sensor malfunction • PCM connector or terminal malfunction • PCM malfunction

DTC P0642:00

Sensor reference circuit low input

DETECTION CONDITION

• The PCM monitors the sensor reference voltage from the EGR valve position sensor, intake shutter valve position sensor, wastegate valve actuator position sensor, MAP sensor and diesel particulate filter differential pressure sensor. If the power supply voltage for the EGR valve position sensor, intake shutter valve position sensor, wastegate valve actuator position sensor, MAP sensor, or diesel particulate filter differential pressure sensor is less than 4.74609 V the PCM determines that the sensor reference voltage circuit has a malfunction.

POSSIBLE CAUSE

• EGR valve position sensor connector or terminal malfunction

• Intake shutter valve position sensor connector or terminal malfunction

• Wastegate valve actuator position sensor connector or terminal malfunction

• MAP sensor connector or terminal malfunction

• Diesel particulate filter differential pressure sensor connector or terminal malfunction

• Short to ground in wiring harness between EGR valve position sensor terminal E and PCM terminal 2AO

• Short to ground in wiring harness between intake shutter valve position sensor terminal A and PCM terminal 2AO

• Short to ground in wiring harness between wastegate valve actuator position sensor terminal B and PCM terminal 2AS

• Short to ground in wiring harness between MAP sensor terminal C and PCM terminal 2AS

• Short to ground in wiring harness between diesel particulate filter differential pressure sensor terminal A and PCM terminal 2AT

• EGR valve position sensor malfunction

• Intake shutter valve position sensor malfunction

• Wastegate valve actuator position sensor malfunction

• MAP sensor malfunction

• Diesel particulate filter differential pressure sensor malfunction

• PCM connector or terminal 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 REPAIR INFORMATION AVAILABILITY • Verify related service repair information availability. • Is any related repair information available?	Yes	Perform repair or diagnosis according to the available repair 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 to ON (engine off). • Perform the Pending Trouble Code Access Procedure and DTC Reading Procedure. (See ON-BOARD DIAGNOSTIC TEST [MZ-CD 1.6].) • Is the other PENDING CODE/DTC also present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [MZ-CD 1.6].)
No	Go to the next step.
4	INSPECT EGR VALVE POSITION SENSOR CONNECTOR CONDITION • Switch the ignition to off. • Disconnect the EGR 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 20.
No	Go to the next step.
5	INSPECT INTAKE SHUTTER VALVE POSITION SENSOR CONNECTOR CONDITION • Disconnect the intake shutter 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 20.
No	Go to the next step.
6	INSPECT WASTEGATE VALVE ACTUATOR POSITION SENSOR CONNECTOR CONDITION • Disconnect the wastegate valve actuator 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 20.
No	Go to the next step.
7	INSPECT MAP SENSOR CONNECTOR CONDITION • Disconnect the MAP 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 20.
No	Go to the next step.
8	INSPECT DIESEL PARTICULATE FILTER DIFFERENTIAL PRESSURE SENSOR CONNECTOR CONDITION • Disconnect the diesel particulate filter differential 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 20.
No	Go to the next step.
9	INSPECT EGR VALVE POSITION SENSOR POWER CIRCUIT FOR SHORT TO GROUND • Disconnect the EGR valve position sensor connector. • Inspect for continuity between EGR valve position sensor terminal E (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 20.
No	Go to the next step.
10	INSPECT INTAKE SHUTTER VALVE POSITION SENSOR POWER CIRCUIT FOR SHORT TO GROUND • Disconnect the intake shutter valve position sensor connector. • Inspect for continuity between intake shutter valve position sensor terminal A (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 20.
No	Go to the next step.
11	INSPECT WASTEGATE VALVE ACTUATOR POSITION SENSOR POWER CIRCUIT FOR SHORT TO GROUND • Disconnect the wastegate valve actuator position sensor connector. • Inspect for continuity between wastegate valve actuator position sensor terminal B (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 20.
No	Go to the next step.
12	INSPECT MAP SENSOR POWER CIRCUIT FOR SHORT TO GROUND • Disconnect the MAP sensor connector. • Inspect for continuity between MAP 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 20.
No	Go to the next step.
13	INSPECT DIESEL PARTICULATE FILTER DIFFERENTIAL PRESSURE SENSOR POWER CIRCUIT FOR SHORT TO GROUND • Disconnect the diesel particulate filter differential pressure sensor connector. • Inspect for continuity between diesel particulate filter differential pressure sensor terminal A (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 20.
No	Go to the next step.
14	INSPECT EGR VALVE POSITION SENSOR • Inspect the EGR valve position sensor. (See EGR VALVE POSITION SENSOR INSPECTION [MZ-CD 1.6].) • Is there any malfunction?	Yes	Replace the EGR valve, then go to Step 20. (See EGR VALVE REMOVAL/INSTALLATION [MZ-CD 1.6].)
No	Go to the next step.
15	INSPECT INTAKE SHUTTER VALVE POSITION SENSOR • Inspect the intake shutter valve position sensor. • Is there any malfunction?	Yes	Replace the intake shutter valve, then go to Step 20. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [MZ-CD 1.6].)
No	Go to the next step.
16	INSPECT WASTEGATE VALVE ACTUATOR POSITION SENSOR • Inspect the wastegate valve actuator position sensor. • Is there any malfunction?	Yes	Replace the wastegate valve actuator position sensor, then go to Step 20.
No	Go to the next step.
17	INSPECT MAP SENSOR • Inspect the MAP sensor. (See MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR INSPECTION [MZ-CD 1.6].) • Is there any malfunction?	Yes	Replace the MAP sensor, then go to Step 20.
No	Go to the next step.
18	INSPECT DIESEL PARTICULATE FILTER DIFFERENTIAL PRESSURE SENSOR • Inspect the diesel particulate filter differential pressure sensor. (See DIESEL PARTICULATE FILTER DIFFERENTIAL PRESSURE SENSOR INSPECTION [MZ-CD 1.6].) • Is there any malfunction?	Yes	Replace the diesel particulate filter differential pressure sensor, then go to Step 20. (See DIESEL PARTICULATE FILTER DIFFERENTIAL PRESSURE SENSOR REMOVAL/INSTALLATION [MZ-CD 1.6].)
No	Go to the next step.
19	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 Step 15.
No	Go to the next step.
20	VERIFY THAT DTC P0642:00 TROUBLESHOOTING IS COMPLETED • Make sure to reconnect all disconnected connectors. • 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	Repeat the inspection from Step 1. • If the malfunction recurs, replace the PCM. (See PCM REMOVAL/INSTALLATION [MZ-CD 1.6].) Go to the next step.
No	Go to the next step.
21	VERIFY AFTER REPAIR PROCEDURE • Perform the after repair procedure. (See AFTER REPAIR PROCEDURE [MZ-CD 1.6].) • Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [MZ-CD 1.6].)
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 REPAIR INFORMATION AVAILABILITY

• Verify related service repair information availability.

• Is any related repair information available?

Yes

Perform repair or diagnosis according to the available repair information.

• If the vehicle is not repaired, go to the next step.

Go to the next step.

VERIFY RELATED PENDING CODE AND/OR DTC

• Switch the ignition to ON (engine off).

• Perform the Pending Trouble Code Access Procedure and DTC Reading Procedure.

(See ON-BOARD DIAGNOSTIC TEST [MZ-CD 1.6].)

• Is the other PENDING CODE/DTC also present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [MZ-CD 1.6].)

Go to the next step.

INSPECT EGR VALVE POSITION SENSOR CONNECTOR CONDITION

• Switch the ignition to off.

• Disconnect the EGR 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 20.

Go to the next step.

INSPECT INTAKE SHUTTER VALVE POSITION SENSOR CONNECTOR CONDITION

• Disconnect the intake shutter 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 20.

Go to the next step.

INSPECT WASTEGATE VALVE ACTUATOR POSITION SENSOR CONNECTOR CONDITION

• Disconnect the wastegate valve actuator 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 20.

Go to the next step.

INSPECT MAP SENSOR CONNECTOR CONDITION

• Disconnect the MAP 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 20.

Go to the next step.

INSPECT DIESEL PARTICULATE FILTER DIFFERENTIAL PRESSURE SENSOR CONNECTOR CONDITION

• Disconnect the diesel particulate filter differential 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 20.

Go to the next step.

INSPECT EGR VALVE POSITION SENSOR POWER CIRCUIT FOR SHORT TO GROUND

• Disconnect the EGR valve position sensor connector.

• Inspect for continuity between EGR valve position sensor terminal E (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 20.

Go to the next step.

INSPECT INTAKE SHUTTER VALVE POSITION SENSOR POWER CIRCUIT FOR SHORT TO GROUND

• Disconnect the intake shutter valve position sensor connector.

• Inspect for continuity between intake shutter valve position sensor terminal A (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 20.

Go to the next step.

INSPECT WASTEGATE VALVE ACTUATOR POSITION SENSOR POWER CIRCUIT FOR SHORT TO GROUND

• Disconnect the wastegate valve actuator position sensor connector.

• Inspect for continuity between wastegate valve actuator position sensor terminal B (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 20.

Go to the next step.

INSPECT MAP SENSOR POWER CIRCUIT FOR SHORT TO GROUND

• Disconnect the MAP sensor connector.

• Inspect for continuity between MAP 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 20.

Go to the next step.

INSPECT DIESEL PARTICULATE FILTER DIFFERENTIAL PRESSURE SENSOR POWER CIRCUIT FOR SHORT TO GROUND

• Disconnect the diesel particulate filter differential pressure sensor connector.

• Inspect for continuity between diesel particulate filter differential pressure sensor terminal A (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 20.

Go to the next step.

INSPECT EGR VALVE POSITION SENSOR

• Inspect the EGR valve position sensor.

(See EGR VALVE POSITION SENSOR INSPECTION [MZ-CD 1.6].)

• Is there any malfunction?

Yes

Replace the EGR valve, then go to Step 20.

(See EGR VALVE REMOVAL/INSTALLATION [MZ-CD 1.6].)

Go to the next step.

INSPECT INTAKE SHUTTER VALVE POSITION SENSOR

• Inspect the intake shutter valve position sensor.

• Is there any malfunction?

Yes

Replace the intake shutter valve, then go to Step 20.

(See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [MZ-CD 1.6].)

Go to the next step.

INSPECT WASTEGATE VALVE ACTUATOR POSITION SENSOR

• Inspect the wastegate valve actuator position sensor.

• Is there any malfunction?

Yes

Replace the wastegate valve actuator position sensor, then go to Step 20.

Go to the next step.

INSPECT MAP SENSOR

• Inspect the MAP sensor.

(See MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR INSPECTION [MZ-CD 1.6].)

• Is there any malfunction?

Yes

Replace the MAP sensor, then go to Step 20.

Go to the next step.

INSPECT DIESEL PARTICULATE FILTER DIFFERENTIAL PRESSURE SENSOR

• Inspect the diesel particulate filter differential pressure sensor.

(See DIESEL PARTICULATE FILTER DIFFERENTIAL PRESSURE SENSOR INSPECTION [MZ-CD 1.6].)

• Is there any malfunction?

Yes

Replace the diesel particulate filter differential pressure sensor, then go to Step 20.

(See DIESEL PARTICULATE FILTER DIFFERENTIAL PRESSURE SENSOR REMOVAL/INSTALLATION [MZ-CD 1.6].)

Go to the next step.

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 Step 15.

Go to the next step.

VERIFY THAT DTC P0642:00 TROUBLESHOOTING IS COMPLETED

• Make sure to reconnect all disconnected connectors.

• 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

Repeat the inspection from Step 1.

• If the malfunction recurs, replace the PCM.

(See PCM REMOVAL/INSTALLATION [MZ-CD 1.6].)

Go to the next step.

VERIFY AFTER REPAIR PROCEDURE

• Perform the after repair procedure.

(See AFTER REPAIR PROCEDURE [MZ-CD 1.6].)

• Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [MZ-CD 1.6].)

DTC troubleshooting completed.