DTC P084C
DTC P084C: Line 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 deg.F (0 deg.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 vehicle condition is turned to 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 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.