DTC Advanced Diagnostics: P084C
DTC P084C:Line Pressure Pressure Switch Stuck ON

General Description

Line pressure mode combination table
 
Normal line pressure mode
Low line pressure mode
Line pressure solenoid valve A
OFF
ON
Line pressure switch
OFF
ON
Line pressure condition
Normal
Low

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 detect 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
Execution
Continuous
Sequence
None
Duration
5 seconds or more
DTC Type
Two drive cycles, MIL on, A/T gear position indicator blinks
OBD Status
PASSED/FAILED/NOT COMPLETED (STILL TESTING)

Enable Conditions
Condition
Minimum
Maximum
ATF temperature
[ATF TEMPERATURE]*
32 °F (0 °C)
–
Battery voltage
[BATTERY VOLTAGE]
11 V
–
No active DTCs set (prevents monitor from running)
P0122, P0123, P0222, P0223, P0716, P0717, P0718, P0721, P0722, P0723, P0746, P0747, P0751, P0752, P0756, P0757, P0761, P0762, P0776, P0777, P0796, P0797, P0842, P0843, P0847, P0848, P0872, P0873, P0877, P0878, P0962, P0963, P0966, P0967, P0970, P0971, P0973, P0974, P0976, P0977, P0979, P0980, P0989, P0990, P1658, P1659, P1683, P1684, P2101, P2118, P2122, P2123, P2127, P2128, P2135, P2138, P2176, P2714, P2720, P2721
*: Symptom 2

[ ]: HDS Parameter

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 engine start/stop button is pressed to select the ON mode with the engine stopped.

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.
Line pressure switch OPPLSW line short to ground
Line pressure switch stuck on
PCM internal circuit failure

Confirmation Procedure
Operating Condition
1.
Start the engine.
2.
Drive the vehicle in D until the transmission shifts into 6th gear.
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 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, the A/T gear position indicator blinks, and a Confirmed DTC and the freeze data are stored.

Conditions for clearing the DTC
The A/T gear position indicator comes off by pressing the engine start/stop button to select the OFF mode. 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.