DTC P0641
DTC P0641: Sensor Reference Voltage 1 Circuit Malfunction
General Description
The transmission control module (TCM) monitors sensor power supply voltage in the TCM. If the sensor power supply voltage is out of specified range for a specified duration, the TCM detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | 1 second or more |
| DTC Type | One drive cycle, MIL on, A/T gear position indicator blinks |
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| 12 volt battery voltage [Battery Voltage] | 9 V | - |
| Vehicle | ON mode | |
[ ]: HDS Parameter
Malfunction Threshold
The sensor power voltage (VCC2) is more than 9.7 V, or less than 6.7 V, for at least 1 second.
Possible Cause
The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
- TCM VCC2 line open (includes a loose or disconnected connector)
- TCM SG1 line open (includes a loose or disconnected connector)
- TCM VCC2 line short to ground
- Sensor unit failure
- TCM internal failure
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, the A/T gear position indicator blinks, the MIL comes on, and a Pending DTC, a Confirmed DTC, and the freeze data are stored in the TCM memory.
Conditions for clearing the DTC
The A/T gear position indicator comes off by turning the vehicle to the OFF (LOCK) mode. 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.