Advanced Diagnostics

Advanced Diagnostics - DTC P0641: Sensor Reference Voltage A Malfunction






General Description
The powertrain control module (PCM) is equipped with a voltage monitor (5 V power source) to supply a stable 5 V to each sensor as reference voltage. The correct voltage for the sensors are loaded in the CPU of the PCM (A/D input) and when the condition that sensor power voltage is a set value (high or low) continues for a certain time, the PCM detects a malfunction and stores a DTC.

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






Enable Conditions






Malfunction Threshold
The sensor power voltage is 5.2 V or more, or 4.5 V or less, for at least 2.0 seconds.

Diagnosis Details

Conditions for setting the DTC
When a malfunction is detected, the MIL comes on and a Pending DTC, a Confirmed DTC, and the freeze data are stored in the PCM memory.

Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the battery.