P0641-SENSOR SUPPLY 1 VOLTAGE TOO LOW





For a complete wiring diagram Refer to Section 8W


  • When Monitored:

    With the ignition on.

  • Set Condition:

    The ECM detects low voltage on the Sensor Supply #1 circuit which supplies 5-volts to the CMP Sensor and the APP Sensor #1.


Possible Causes
 
WIRING INSPECTION
 
INTERMITTENT CONDITION
 
5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
 
ACCELERATOR PEDAL POSITION SENSOR
 
CAMSHAFT POSITION SENSOR
 
ENGINE CONTROL MODULE
 




Diagnostic Test

1.CHECK FOR ACTIVE DTC

NOTE: If the ECM detects and stores a DTC, the ECM also stores the engine/vehicle operating conditions under which the DTC was set. Some of these conditions are displayed on the scan tool at the same time the DTC is displayed.


NOTE: Before erasing stored DTCs, record these conditions. Attempting to duplicate these conditions may assist when checking for an active DTC.






Did this DTC set again?

Yes
  • Go To2


No

2.CAMSHAFT POSITION SENSOR SHORTED TO GROUND








Is the voltage above 4.6 volts?

Yes


No
  • Go To3

3.ACCELERATOR PEDAL POSITION SENSOR SHORTED TO GROUND








Is the voltage above 4.6 volts?

Yes


No
  • Go To4

4.5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND









Is the resistance above 1000 ohms?

Yes
  • Go To5


No

5.WIRING INSPECTION





Were any problems found?

Yes


No