DTC P2685, P2686
DTC P2685 : Actuator Supply Voltage C Circuit Low
DTC P2686 : Actuator Supply Voltage C Circuit High
General Description
The actuator supply voltage is for the power to drive the CPU in the transmission control module (TCM). From the perspective of a fail-safe, three systems (VB1, VB2, and VB3) of the power supply lines are secured. They also have a role to supply power to the clutch pressure control solenoid valves and the shift solenoid valves. The TCM monitors whether the VB3 voltage is in a normal range by the CPU. If the VB3 voltage is a specified value for a set time, the TCM detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration* | 0.45 second or more |
| Duration** | 3.0 seconds or more |
| DTC Type | One drive cycle, MIL on, shift position indicator blinks |
| *: DTC P2685 **: DTC P2686 |
|
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| 12 volt battery voltage [Battery Voltage] | 9.3 V | - |
| Vehicle | ON mode | |
| Other* | Fail-safe switch is off (actuator power shutdown state) | |
| Other** | Fail-safe switch is off (actuator power shutdown state) or CPU power shutdown state continues for 2.5 seconds or more | |
| [ ]: HDS Parameter | ||
Malfunction Threshold
DTC: P2685
The VB3 voltage is 5.6 V or less for at least 0.45 second.
DTC: P2686
The VB3 voltage is 7.2 V or more for at least 3.0 seconds.
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.
DTC: P2685
- Fuse failure
- Short in fuse circuit
- TCM VB3 line open (includes connector loose connection or disconnection)
Common
- 12 volt battery failure
- TCM internal circuit failure
Confirmation Procedure
Operating Condition
DTC: P2685
Turn the vehicle to the ON mode, and wait for several seconds.
DTC: P2686
- Turn the vehicle to the ON mode.
- Turn the vehicle to the OFF (LOCK) mode, and wait for at least 30 seconds.
- Turn the vehicle to the ON mode, and wait for several seconds.
With the HDS
None.
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, the MIL comes on, the shift position indicator blinks, and a Pending DTC, a Confirmed DTC, and the freeze data are stored in the TCM memory.
Conditions for clearing the DTC
The shift 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.