Nissan Xterra. Manual - part 310
EC-366
< DTC/CIRCUIT DIAGNOSIS >
[VQ40DE]
P0643 SENSOR POWER SUPPLY
P0643 SENSOR POWER SUPPLY
On Board Diagnosis Logic
INFOID:0000000009484090
This self-diagnosis has the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation Procedure
INFOID:0000000009484091
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.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10V at idle.
1. Start engine and let it idle for 1 second.
2. Check 1st trip DTC.
3. If DTC is detected, go to
.
Diagnosis Procedure
INFOID:0000000009484092
1.
CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground three screws on the body. Refer to
DTC No.
Trouble diagnosis
name
DTC detecting condition
Possible cause
P0643
0643
Sensor power supply
circuit short
ECM detects that the voltage of power
source for sensor is excessively low or high.
• Harness or connectors
(APP sensor 1 circuit is shorted.)
(PSP sensor circuit is shorted.)
(Refrigerant pressure sensor circuit is short-
ed.)
(Battery current sensor circuit is shorted.)
(EVAP control system pressure sensor circuit
is shorted.)
• Accelerator pedal position sensor
(APP sensor 1)
• EVAP control system pressure sensor
• Power steering pressure sensor
• Refrigerant pressure sensor
• Battery current sensor
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.
BBIA0539E