DTC P173B: General Description

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

Shift solenoid valve A is installed on the transmission housing. It is controlled by the ON/OFF signal from the powertrain control module (PCM) to apply line pressure to shift valve A. The signal from the PCM is output so that the line pressure is supplied to the clutch piston under the condition that overdrive clutch engagement is requested during running at 44 mph (70 km/h) or more. When the signal to shift solenoid valve A from the PCM is on, and the line pressure is applied to shift valve A, it operates against the shift valve A spring. When the signal to shift solenoid valve A from the PCM is off, and the line pressure is discharged, shift valve A is inactive. The PCM monitors the transmission fluid pressure sensor. If the transmission fluid pressure sensor pressure is a specified value or less when the engine is stopped or engagement of the over drive clutch is requested, the PCM detects a malfunction and stores a DTC.