DTC P0872 (6-Speed A/T)

DTC P0872  : Transmission Fluid Pressure Switch C (4th Clutch) Circuit Low

NOTE: 

• Before you troubleshoot, review the General Troubleshooting Information - Refer to: How to Troubleshoot the A/T System .
• This code is caused by an electrical circuit problem and cannot be caused by a mechanical problem in the transmission.
• If DTC P0872 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. 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 

   The failure is duplicated. Go to step 2.

   NO 

   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.

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. Turn the vehicle to the ON mode.

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

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

   Do the current condition (s) match the threshold?

   YES 

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

   NO 

   Go to step 3.

3. Shorted wire check (OP4SW line)

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

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

   - 3. Disconnect the following connector.

   PCM connector B (51P)

   - 4. 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	PCM connector B (51P) No. 26 - Refer to: PCM Connector for Inputs and Outputs (16-20 6-Speed A/T) .
   Test point 2	Body ground

   Is there continuity?

   YES 

   Repair a short to ground in the OP4SW wire between transmission fluid pressure switch C (4th clutch) and the PCM.

   NO 

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