DTC P0873 (6-Speed A/T)

DTC P0873  : Transmission Fluid Pressure Switch C (4th Clutch) Circuit High

NOTE: 

• Before you troubleshoot, review the General Troubleshooting Information - Refer to: How to Troubleshoot the A/T System .
• If DTC P0873 is stored in the PCM, the transmission does not shift to any gear other than 1st or 4th gear because of the fail-safe function.

DTC (A/T)

1. Problem verification

   - 1. Turn the vehicle to the ON mode.

   - 2. Clear the DTC with the HDS.

   - 3. Raise the vehicle on a lift. Make sure it is securely supported, and allow all four wheels to rotate freely.

   - 4. Start the engine.

   - 5. Disable the VSA by pressing the VSA OFF button.

   NOTE: Enter the VSA maintenance mode in case of the vehicle speed above 31 mph (50 km/h).

   - 6. Run the vehicle in 4th gear, and check the parameter (s) below with the HDS. Slow down, and stop the wheels.

   Signal	Threshold		Current conditions
   	Values	Unit	Values	Unit
   4th Pressure Switch	ON

   Do the current condition (s) match the threshold in 4th gear?

   YES 

   Intermittent failure, the system is OK at this time. Check for poor connections and loose terminals between transmission fluid pressure switch C (4th clutch) and the PCM. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the freeze data/on-board snapshot.

   NO 

   The failure is duplicated. Go to step 2.

2. Determine possible failure area (transmission fluid pressure switch C (4th clutch), others)

   - 1. Turn the vehicle to the OFF (LOCK) mode.

   - 2. Disconnect the following connector.

   Transmission fluid pressure switch C (4th clutch) 1P connector

   - 3. Connect terminals A and B with a jumper wire.

   Terminal A	Transmission fluid pressure switch C (4th clutch) 1P connector No. 1
   Terminal B	Body ground

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

   - 4. Turn the vehicle to the ON mode.

   - 5. Check the parameter (s) below with the HDS.

   Signal	Threshold		Current conditions
   	Values	Unit	Values	Unit
   4th Pressure Switch	ON

   Do the current condition (s) match the threshold?

   YES 

   Replace transmission fluid pressure switch C (4th clutch) .

   NO 

   Go to step 3.

3. Open wire check (OP4SW line)

   - 1. Turn the vehicle to the OFF (LOCK) mode.

   - 2. Remove the jumper wire.

   - 3. Jump the SCS line with the HDS, and wait more than 1 minute.

   - 4. Disconnect the following connector.

   PCM connector B (51P)

   - 5. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	Transmission fluid pressure switch C (4th clutch) 1P connector: disconnected
   	PCM connector B (51P): disconnected
   Test point 1	Transmission fluid pressure switch C (4th clutch) 1P connector No. 1
   Test point 2	PCM connector B (51P) No. 26 - Refer to: PCM Connector for Inputs and Outputs (16-20 6-Speed A/T)

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

   Is there continuity?

   YES 

   The OP4SW wire is OK. Replace the PCM - Refer to: PCM Removal and Installation (6-Speed A/T, 16-18 9-Speed A/T) .

   NO 

   Repair an open in the OP4SW wire between transmission fluid pressure switch C (4th clutch) and the PCM.