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DTC Advanced Diagnostics: P2821

DTC P2821  : Clutch Pressure Control Solenoid Valve A Stuck ON

General Description 

GHH477627Courtesy of HONDA, U.S.A., INC.

Operation Chart 

Shift Position/Mode Clutch Pressure Control Solenoid Valve Operation Shift Solenoid Valve Operation
A B C D E F G H A B C D E F G
P x x/o x x x x x x o/x o/x x o x o x
R o/x o x x x o x x o o x x o x x
R* o o x o o x x x x->o x->o x x o x x
N x x/o x x x x x x o/x o/x o o o x x

o: Operated (Clutch pressure control solenoid valve is linear controlled or shift solenoid valve is ON.)x: Not operated (Clutch pressure control solenoid valve and shift solenoid valve are OFF.)*: Reverse preparation**: Select from 6th only

Shift Position/Mode Clutch Pressure Control Solenoid Valve Operation Shift Solenoid Valve Operation
A B C D E F G H A B C D E F G
D Low o/x x x x x o o o/x x x o/x x o x x
2nd o/x x o x x o o o/x x x o/x x o x x
3rd o/x o x x x o o o/x x x o/x x o x x
4th o/x o o x x x o o/x x x o/x x o x x
5th-A o/x o x o x x o o/x x x o/x x o x x
5th-B** o/x x o o x x o o/x x x o/x x o x x
6th o/x o o o x x x o/x x x o/x x o x x
7th o/x o x o x o x o/x x x o/x x o x x
8th o/x x o o x o x o/x x x o/x x o x x
9th o/x x x o o o x o/x x x o/x x o x x
10th o/x x o o o x x o/x x x o/x x o x x

o: Operated (Clutch pressure control solenoid valve is linear controlled or shift solenoid valve is ON.)x: Not operated (Clutch pressure control solenoid valve and shift solenoid valve are OFF.)*: Reverse preparation**: Select from 6th only

Clutch pressure control solenoid valve A controls the line pressure in the hydraulic circuit. A spool in clutch pressure control solenoid valve A pushes the valve according to the duty cycle controlled by the transmission control module (TCM) (the hydraulic pressure is proportional to the current). Each transmission fluid pressure sensor value while steady forward driving (except steady 1st gear ratio) or while reverse preparation (from reverse shifting command to completion) is monitored, and if the transmission fluid pressure sensor value is within a specified range, the TCM detects a clutch pressure control solenoid valve A stuck on failure and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type 

Execution Continuous
Sequence None
Duration Depending on the driving conditions
DTC Type Two drive cycles, MIL on, shift position indicator blinks

Enable Conditions 

Condition Minimum Maximum
Engine speed [Engine Speed] - 4, 000 rpm
12 volt battery voltage [Battery Voltage] 10 V -
Line pressure commanded pressure - 900 kPa (9.17 kgf/cm 2, 130.5 psi)
Other Steady 2nd to 10th gear ratio or reverse preparation
The engine speed [Engine Speed] to permit execution of the malfunction diagnosis must be the value or more shown in the following graph depending on the ATF temperature sensor value [ATF Temperature]

[ ]:HDS Parameter

GHH477628Courtesy of HONDA, U.S.A., INC.

Malfunction Threshold 

Transmission fluid pressure sensor value 1 and 2 are within the range from 1, 600 kPa (16.32 kgf/cm 2, 232.1 psi) to 2, 500 kPa (25.49 kgf/cm 2, 362.6 psi) at each condition of the transmission control mode.

Transmission control mode  Transmission fluid pressure sensor value 1  Transmission fluid pressure sensor value 2 
Steady 2nd gear ratio Transmission fluid pressure sensor F Transmission fluid pressure sensor E
Steady 3rd gear ratio Transmission fluid pressure sensor F Transmission fluid pressure sensor A
Steady 4th gear ratio Transmission fluid pressure sensor F Transmission fluid pressure sensor A
Steady 5th gear ratio Transmission fluid pressure sensor F Transmission fluid pressure sensor C
Steady 6th gear ratio Transmission fluid pressure sensor C Transmission fluid pressure sensor A
Steady 7th gear ratio Transmission fluid pressure sensor C Transmission fluid pressure sensor A
Steady 8th gear ratio Transmission fluid pressure sensor C Transmission fluid pressure sensor E
Steady 9th gear ratio Transmission fluid pressure sensor C Transmission fluid pressure sensor E
Steady 10th gear ratio Transmission fluid pressure sensor C Transmission fluid pressure sensor B
Reverse preparation Transmission fluid pressure sensor C Transmission fluid pressure sensor A

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.

Confirmation Procedure 

Operating Condition 

Diagnosis Details 

Conditions for setting the DTC 

When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the TCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on, the shift position indicator blinks, and a Confirmed DTC and the freeze data are stored.

Conditions for clearing the DTC 

The shift position indicator comes off by turning the vehicle to the OFF (LOCK) 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.