LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Acura >> 2021 >> TLX Base >> Repair and Diagnosis >> Transmission >> Automatic Trans >> Automatic Transaxle - Advanced Diagnostics >> Advanced Diagnostics >> DTC Advanced Diagnostics: P2670, P2671
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC Advanced Diagnostics: P2670, P2671

DTC P2670  : Actuator Supply Voltage B Circuit Low DTC P2671  : Actuator Supply Voltage B Circuit High

General Description 

GHH477607Courtesy of HONDA, U.S.A., INC.

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 VB2 voltage is in a normal range by the CPU. If the VB2 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* 0.5 second or more
Duration** 0.6 second or more
DTC Type One drive cycle, MIL on, shift position indicator blinks

*: DTC P2670

**: DTC P2671

Enable Conditions 

Condition Minimum Maximum
Elapsed time after the vehicle condition is turned to the OFF (LOCK) mode** 30 seconds -
12 volt battery voltage [Battery Voltage] 10 V -
Vehicle ON mode
Other* Fail-safe switch is on (actuator power supplied state)

[ ]: HDS Parameter

Malfunction Threshold 

DTC: P2670 

The VB2 voltage is 5.6 V or less for at least 0.5 second.

DTC: P2671 

The VB2 voltage is 7.2 V or more for at least 0.6 second.

Possible Cause 

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.

DTC: P2670 

Common 

Confirmation Procedure 

Operating Condition 

DTC: P2670 

Turn the vehicle to the ON mode, and wait for several seconds.

DTC: P2671 

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.