Advanced Diagnostics

Advanced Diagnostics - DTC P2821: Line Pressure Solenoid Valve A Stuck ON

General Description











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 normal line pressure. 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 the signal from the PCM is ON, the line pressure is regulated to low line pressure, and when the signal from the PCM is OFF, the line pressure is regulated to normal line pressure. If the PCM detects a clutch slippage during normal line pressure mode, a malfunction is detected and stores a DTC.

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






Enable Conditions






Malfunction Threshold
The clutch speed difference between the speed input to the clutch and the speed output from the clutch is 5 rpm or more for at least 2 seconds.

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

With the HDS
None.

With the Driving Pattern
1. Start the engine, and let it idle until the radiator fan comes on.
2. Drive the vehicle in 4th gear at a speed of 37 mph (60 km/h) or more with the accelerator pedal position at 50 % or more for at least 5 seconds or more.

- 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.