DTC P0843: Transmission Fluid Pressure Switch A (2nd Clutch) Circuit High (2013-17)

General Description 

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

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

Transmission fluid pressure switch A (2nd clutch) is installed in the hydraulic pressure circuit to the 2nd clutch. When hydraulic pressure is supplied to the 2nd clutch, the switch is turned on. When hydraulic pressure is not supplied to the 2nd clutch, the switch is turned off. The signal from transmission fluid pressure switch A (2nd clutch) is input to the powertrain control module (PCM). The PCM detects the hydraulic pressure supply conditions at the gear change to 2nd gear (1st ? 2nd) to reduce the shock that occurs at the gear change. If transmission fluid pressure switch A (2nd clutch) is off while driving the vehicle with the rotation speed ratio of the input/output pulses is that of the 2nd gear ratio, the PCM detects a transmission fluid pressure switch A (2nd clutch) failure and stores a DTC.

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

Execution		Continuous
Sequence		None
Duration		4 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
Battery voltage [BATTERY VOLTAGE]		11 V	-
	No active DTCs set (prevents monitor from running)		P0122, P0123, P0222, P0223, P0705, P0716, P0717, P0718, P0721, P0722, P0723, P0746, P0747, P0751, P0752, P0756, P0757, P0761, P0762, P0776, P0777, P0796, P0797, P0842, 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

[ ]: HDS Parameter

Malfunction Threshold 

The input signal from transmission fluid pressure switch A (2nd clutch) [2ND PRESSURE SWITCH] to the PCM is high when driving in 2nd gear.

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.

• Transmission fluid pressure switch A (2nd clutch) OP2 SW*¹ (OP2SW)*² line short to power
• Transmission fluid pressure switch A (2nd clutch) OP2 SW*¹ (OP2SW)*² line open (includes connector loose connection or disconnection)
• Transmission fluid pressure switch A (2nd clutch) stuck off
• PCM internal circuit failure

*1: 2013 - 2015 models *2: 2016 model on and after

Confirmation Procedure 

With the HDS 

None.

With the Driving Pattern 

• 1.

  Start the engine.

• 2.

  Drive the vehicle in 2nd gear for at least 4 seconds.

• 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.