DTC P2821

DTC P2821: Line Pressure Solenoid Valve A Stuck ON

General Description

Courtesy of HONDA, U.S.A., INC.

The line pressure control solenoid valve is used for line pressure control. A spool in the line pressure control solenoid valve pushes the valve according to the duty cycle that is controlled by the powertrain control module (PCM) (The hydraulic pressure is proportional to the current). A current is output from the PCM to provide optimum line pressure depending on driving condition. When the output current is 0 A, the line pressure is provided maximum (3, 000 kPa (30.59 kgf/cm2, 435 psi)), and when the output current is 1.2 A, the line pressure is provided minimum (650 kPa (6.63 kgf/cm2, 94 psi)). If the output value of the odd clutch pressure sensor, the even clutch pressure sensor, or the reverse clutch pressure sensor is abnormal from the PCM commanded line pressure value, the PCM detects a line pressure control solenoid valve stuck on failure and stores a DTC.

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

Execution	Continuous
Sequence	None
Duration	2 seconds or less
DTC Type	One drive cycle, MIL on, A/T gear position indicator blinks
OBD Status	PASSED/FAILED/NOT COMPLETED (STILL TESTING)

Enable Conditions

Condition	Minimum	Maximum
Engine speed [Engine Speed]	500 RPM	-
Battery voltage [Battery Voltage]	11 V	-
No active DTCs set (prevents monitor from running)	P0716, P0717, P0718, P0721, P0722, P0723, P0746, P0747, P0751, P0752, P0756, P0757, P0761, P0762, P0766, P0767, P0771, P0772, P0776, P0777, P0792, P0793, P0794, P0796, P0797, P0841, P0842, P0843, P0846, P0847, P0848, P0871, P0872, P0873, P0962, P0963, P0966, P0967, P0970, P0971, P0973, P0974, P0976, P0977, P0979, P0980, P0982, P0983, P0985, P0986, P2714, P2715, P2720, P2721, P2729, P2730, P2746, P2747, P2748, P2820, P2826, P2827, P2832, P2833, P2834, P2837, P2838, P2839, P283C, P283D, P283E, P2841, P2842, P2843, P2845, P2846, P2847, P2848
Other	High line pressure mode is detected by odd clutch pressure sensor or even clutch pressure sensor

[ ]: HDS Parameter

Malfunction Threshold

One of these conditions occurs:

The odd clutch pressure sensor output is more than 450 kPa (4.58 kgf/cm2, 65 psi), or less than 850 kPa (8.67 kgf/cm2, 123 psi) when the secondary clutch is commanded high line pressure mode and with odd gear engaged.
The even clutch pressure sensor output is more than 450 kPa (4.58 kgf/cm2, 65 psi), or less than 850 kPa (8.67 kgf/cm2, 123 psi) when the main clutch is commanded high line pressure mode and with even gear engaged.
The reverse clutch pressure sensor output is more than 450 kPa (4.58 kgf/cm2, 65 psi), or less than 850 kPa (8.67 kgf/cm2, 123 psi).

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 control solenoid valve stuck on

Confirmation Procedure

With the HDS

None.

With the Driving Pattern

Start the engine.
With the brake pedal pressed, place the shift lever in R position/mode for at least 5 seconds.

Diagnosis Details

Conditions for setting the DTC

When a malfunction is detected, the MIL comes on and a Pending DTC, a Confirmed DTC, and the freeze data are stored in the PCM memory.

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.