DTC P172B

DTC P172B: KEY-Release Switch Input Circuit Malfunction

General Description

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

The SBW shifter control module in the SBW shifter assembly has a key release switch. By operating the key release switch, it unlocks the parking position in the transmission. The key release switch is composed of KRLSSW1 and KRLSSW2, and when the input signal logic does not match for a specified duration, the powertrain control module (PCM) receives malfunction from the SBW shifter control module, and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type

Execution	Continuous
Sequence	None
Duration	1 minute or more
DTC Type	One drive cycle, MIL off, Shift position indicator off

Enable Conditions

Condition
Vehicle	ON mode

Malfunction Threshold

The input signal logic of KRLSSW1 and KRLSSW2 does not match (KRLSSW1 ON/KRLSSW2 OFF or KRLSSW1 OFF/KRLSSW2 ON) for at least 1 minute.

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.

SBW shifter assembly internal failure

Confirmation Procedure

Operating Condition

Turn the vehicle to the ON mode, and wait for at least 1 minute.

With the HDS

None.

Diagnosis Details

Conditions for setting the DTC

When a malfunction is detected, a Pending DTC, a Confirmed DTC, and the freeze data are stored in the PCM memory. The MIL does not come on and the shift position indicator does not blink.

Conditions for clearing the DTC

The Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the 12 volt battery.