Advanced Diagnostics

DTC P0641: Sensor Reference Voltage A Malfunction

General Description
The engine control module (ECM)/powertrain control module (PCM) is equipped with a voltage monitor (5 V power source for sensor) to supply 5 V to each sensor, and it supplies stable power to each sensor as reference voltage.

The correct voltage for the sensors are loaded in the CPU of the ECM/PCM (A/D input) and when the condition that sensor power voltage is set value or more (high) or set value or less (low) continues for a certain time, a malfunction is detected and a DTC is stored.




Monitor Execution, Sequence, Duration, DTC Type, OBD Status




Enable Conditions

Malfunction Threshold
The sensor power voltage is 5.4 V or more, or 4.6 V or less for at least 2 seconds.

Diagnosis Details

Conditions for illuminating the MIL
When a malfunction is detected, the MIL comes on and the DTC and the freeze frame data are stored in the ECM/PCM memory.

Conditions for clearing the MIL
The MIL will be cleared if the malfunction does not recur during three consecutive trips in which the diagnostic runs.

The MIL, the DTC, and the freeze frame data can be cleared by using the scan tool Clear command or by disconnecting the battery.