Advanced Diagnostics

Advanced Diagnostics - DTC P084C: Short In Line Pressure Switch Circuit, Or Line Pressure Switch Stuck ON











General Description
The line pressure switch is installed in the hydraulic pressure output circuit from line pressure solenoid valve A. When line pressure solenoid valve A outputs hydraulic pressure, the line pressure is regulated to low line pressure and the switch is turned on. When line pressure solenoid valve A does not output hydraulic pressure, the line pressure is at normal line pressure and the switch is turned off. The signal from the line pressure switch is input to the powertrain control module (PCM). The PCM detects the hydraulic pressure supply condition from line pressure solenoid valve A to detects a malfunction in line pressure solenoid valve A. If the line pressure switch is on against the command to turn off line pressure solenoid valve A, the PCM detects a line pressure switch stuck on failure and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type, OBD Status






Enable Conditions






Malfunction Threshold
One of these symptoms occurs:
- Symptom 1
The input signal from the line pressure switch to the PCM is low during the self shut down mode after the signal is low when the normal line pressure mode was commanded.

- Symptom 2
The input signal from the line pressure switch to the PCM is low when the ignition switch is in ON (II) or the engine start/stop button is in the ON mode with the engine stopped.

Driving Pattern
1. Start the engine
2. Drive the vehicle until the transmission shifts into 6th gear.

- Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.

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, the MIL comes on and a Confirmed DTC and the freeze data are stored.

Conditions for clearing the DTC
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 or by disconnecting the battery.