DTC P2821
DTC P2821: Line Pressure Solenoid Valve A 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 |
Line pressure solenoid valve A is installed on the transmission housing. It is controlled by the ON/OFF signal from the powertrain control module (PCM) to regulate line pressure to low line pressure or to normal line pressure. The line pressure switch is installed in the hydraulic pressure output circuit from line pressure solenoid valve A. The signal to line pressure solenoid valve A from the PCM is output to regulate line pressure to proper pressure according to the driving conditions. 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. If the line pressure switch is on against the command to turn off line pressure solenoid valve A, the PCM detects a line pressure solenoid valve A stuck on failure and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | 5 seconds or more |
| DTC Type | Two drive cycles, MIL on, A/T gear position indicator blinks |
Enable Conditions
| Condition | Minimum | Maximum | |
|---|---|---|---|
| 12 volt battery voltage [BATTERY VOLTAGE] | 11 V | - | |
[ ]: HDS Parameter
Malfunction Threshold
The input signal from the line pressure switch to the PCM is high during the self shut down mode after the signal is low when the normal line pressure mode was commanded.
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 solenoid valve A stuck on
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 12 volt battery.