DTC P173A (2020)
DTC P173A : Transmission Fluid Pressure Sensor Performance High
General Description
| Condition of over drive clutch | Shift solenoid valve A | ||
| ON (12 V) | OFF (0 V) | ||
| Shift solenoid valve B | ON (12 V) | ON (engaged) | OFF (disengaged) |
| OFF (0 V) | OFF (disengaged) | OFF (disengaged) | |
Shift solenoid valve A is installed on the flywheel 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 more when the engine is stopped or engagement of the over drive clutch is not requested, the PCM detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | 3.0 seconds or more |
| DTC Type | One drive cycle, MIL off, shift position indicator blinks |
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| 12 volt battery voltage [Battery Voltage] | 11 V | - |
[ ]: HDS Parameter
Malfunction Threshold
The transmission fluid pressure sensor output value is 177 kPa (1327 mmHg, 52.3 inHg) or more for at least 3.0 seconds when the engine is stopped or the engagement of the over drive clutch is not requested.
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.
- Transmission fluid pressure sensor failure
- PCM internal failure
Confirmation Procedure
Operating Condition
- Enter the maintenance mode, then start the engine. Hold the engine speed [ENGINE SPEED] at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
- Drive the vehicle at speed of 44 mph (70 km/h) or less for at least 10 seconds.
- Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.
With the HDS
None.
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, the shift position indicator blinks and a Pending DTC, a Confirmed DTC, and the freeze data are stored in the PCM memory. The MIL does not come on.
Conditions for clearing the DTC
The shift position indicator comes off by turning the vehicle to the OFF (LOCK) mode. 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.