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DTC P170F

DTC P170F:  Park Pawl Unit Communication Circuit (PWM)

General Description 

GHH416831Courtesy of HONDA, U.S.A., INC.

The park pawl actuator driver unit controls shifting/releasing of the park pawl actuator to/from the P position. The park pawl actuator driver unit usually uses two communication lines (EPP-CAN A_H and EPP-CAN A_L) to receive the shifting to/releasing from P position commands from powertrain control module (PCM) and to transmit/receive the feedback signals from the park pawl actuator driver unit to/from the PCM. If communication via EPP-CAN is not available, it is also possible as an alternative method to transmit and receive via PWM communication using the communication line for shifting / releasing (PARKCMD) and the communication line for the feedback signals (PARKBUSY). The PCM and the park pawl actuator driver unit monitor the PWM communication together, and if transmitting and receiving are not available or if abnormal content continues to be received for a specified length of time or more, the PCM receives malfunction from the park pawl actuator driver unit, and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type 

Execution -
Sequence None
Duration 1.5 seconds or more
DTC Type Two drive cycle, MIL off, Shift position indicator off

Enable Conditions 

Condition Minimum Maximum
12 volt battery voltage [Battery Voltage] 10 V -

[ ]: HDS Parameter

Malfunction Threshold 

The park pawl actuator driver unit cannot transmit/receive via PWM communication, or an abnormal signal continues to be received for at least 1.5 seconds.

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.
  • Park pawl actuator driver unit PARKCMD line open (includes a loose or disconnected connector)
  • Park pawl actuator driver unit PARKBUSY line open (includes a loose or disconnected connector)
  • Park pawl actuator driver unit PARKCMD line short to ground
  • Park pawl actuator driver unit PARKBUSY line short to ground
  • Park pawl actuator driver unit PARKCMD line short to power
  • Park pawl actuator driver unit PARKBUSY line short to power
  • Park pawl actuator driver unit internal failure
  • PCM internal failure

Confirmation Procedure 

Operating Condition 

Turn the vehicle to the ON mode, and wait for at least 10 seconds.

With the HDS 

None.

Diagnosis Details 

Conditions for setting the DTC 

When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, a Confirmed DTC and the freeze data are stored. 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.