P0643 SENSOR POWER SUPPLY
< COMPONENT DIAGNOSIS > [VQ40DE]
P0643 SENSOR POWER SUPPLY
A
On Board Diagnosis Logic INFOID:0000000003032161
This self-diagnosis has the one trip detection logic. EC
Trouble diagnosis
DTC No. DTC detecting condition Possible cause
name
C
• Harness or connectors
(APP sensor 1 circuit is shorted.)
(PSP sensor circuit is shorted.)
(Refrigerant pressure sensor circuit is short- D
ed.)
(Battery current sensor circuit is shorted.)
P0643 Sensor power supply ECM detects a voltage of power source for (EVAP control system pressure sensor circuit
0643 circuit short sensor is excessively low or high. is shorted.)
E
• Accelerator pedal position sensor
(APP sensor 1)
• EVAP control system pressure sensor F
• Power steering pressure sensor
• Refrigerant pressure sensor
• Battery current sensor
G
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
H
Engine operation condition in fail-safe mode
ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return
spring. I
DTC Confirmation Procedure INFOID:0000000003032162
NOTE: J
If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-
ing the next step.
1. Turn ignition switch OFF and wait at least 10 seconds. K
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10V at idle. L
1. Start engine and let it idle for 1 second.
2. Check 1st trip DTC.
M
3. If DTC is detected, go to EC-761, "Diagnosis Procedure".
Diagnosis Procedure INFOID:0000000003032163
N
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground three screws on the body. Refer to EC-545, "Ground Inspection". O
BBIA0539E
Revision: March 2010 EC-761 2008 Frontier
P0643 SENSOR POWER SUPPLY
< COMPONENT DIAGNOSIS > [VQ40DE]
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK ACCELERATOR PEDAL POSITION SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect accelerator pedal position (APP) sensor harness connector.
BBIA0556E
2. Turn ignition switch ON.
3. Check voltage between APP sensor terminal 2 and ground with
CONSULT-III or tester.
Voltage: Approximately 5V
OK or NG
OK >> GO TO 5.
NG >> GO TO 3.
PBIB2608E
3.CHECK SENSOR POWER SUPPLY CIRCUITS
Check harness for short to power and short to ground, between the following terminals.
ECM terminal Sensor terminal Reference Wiring Diagram
48 EVAP control system pressure sensor terminal 3
Refrigerant pressure sensor terminal 3
49
Battery current sensor terminal 1 EC-902
68 PSP sensor terminal 3
90 APP sensor terminal 2
OK or NG
OK >> GO TO 4.
NG >> Repair short to ground or short to power in harness or connectors.
4.CHECK COMPONENTS
Check the following.
• EVAP control system pressure sensor (Refer to EC-716, "Component Inspection".)
• Refrigerant pressure sensor (Refer to EC-883, "Component Description".)
• Battery current sensor (Refer to EC-783, "Component Inspection".)
• Power steering pressure sensor (Refer to EC-756, "Component Inspection".)
OK or NG
OK >> GO TO 5.
NG >> Replace malfunctioning component.
5.CHECK APP SENSOR
Refer to EC-832, "Component Inspection".
OK or NG
OK >> GO TO 7.
Revision: March 2010 EC-762 2008 Frontier
P0643 SENSOR POWER SUPPLY
< COMPONENT DIAGNOSIS > [VQ40DE]
NG >> GO TO 6.
6.REPLACE ACCELERATOR PEDAL ASSEMBLY A
1. Replace accelerator pedal assembly.
2. Perform EC-475, "Accelerator Pedal Released Position Learning".
EC
3. Perform EC-475, "Throttle Valve Closed Position Learning".
4. Perform EC-475, "Idle Air Volume Learning".
C
>> INSPECTION END
7.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "Intermittent Incident". D
>> INSPECTION END
E
Revision: March 2010 EC-763 2008 Frontier
P0850 PNP SWITCH
< COMPONENT DIAGNOSIS > [VQ40DE]
P0850 PNP SWITCH
Component Description INFOID:0000000003032164
When the shift lever position is Neutral, park/neutral position (PNP) switch is ON. (M/T)
When the selector lever position is P or N, park/neutral position (PNP) signal is sent to ECM from TCM via-
combination meter (unified meter control unit). (A/T)
ECM detects the position because the continuity of the line (the ON signal) exists.
On Board Diagnosis Logic INFOID:0000000003032165
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
• Harness or connectors
[The park/neutral position (PNP) signal
The park/neutral position (PNP) signal is not circuit is open or shorted.]
P0850 Park/neutral position
changed in the process of engine starting and • Park/neutral position (PNP) switch (M/T)
0850 switch
driving. • Transmission range switch (A/T)
• Combination meter
• TCM (A/T models)
DTC Confirmation Procedure INFOID:0000000003032166
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-
ing the next step.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
WITH CONSULT-III
1. Turn ignition switch ON.
2. Select “P/N POSI SW” in “DATA MONITOR” mode with CONSULT-III. Then check the “P/N POSI SW” sig-
nal under the following conditions.
Position (Selector lever) Known-good signal
P or N position (A/T)
ON
Neutral position (M/T)
Except above position OFF
If NG, go to EC-765, "Diagnosis Procedure".
If OK, go to following step.
3. Select “DATA MONITOR” mode with CONSULT-III.
4. Start engine and warm it up to normal operating temperature.
5. Maintain the following conditions for at least 60 consecutive seconds.
ENG SPEED 1,400 - 6,375 rpm
COOLAN TEMP/S More than 70°C (158°F)
B/FUEL SCHDL 2.0 - 31.8 msec
VHCL SPEED SE More than 64 km/h (40 MPH)
Selector lever Suitable position
6. Check 1st trip DTC.
7. If 1st trip DTC is detected, go to EC-765, "Diagnosis Procedure".
Revision: March 2010 EC-764
Copyright 2009 - 2013 Service Repair Solutions, Inc. 2008 Frontier
