DTC Troubleshooting: P0842 (25-3)

DTC P0842:

Short in 2nd Clutch Transmission Fluid Pressure Switch Circuit, or 2nd Clutch Transmission Fluid Pressure Switch Stuck ON

• Before you troubleshoot, record all freeze data and any on-board snapshot, and review General Troubleshooting Information.
• This code is caused by an electrical circuit problem and cannot be caused by a mechanical problem in the transmission.

1.	Clear the DTC with the HDS.

2.	Check the 2nd PRES SWITCH signal with the HDS in the A/T data list when not in 2nd gear. Is the 2nd PRES SWITCH OFF? YES - Go to 3. NO - Go to 6.

3.	Start the engine, and warm it up to normal operating temperature (the radiator fan comes on).

4.	Drive the vehicle in 2nd gear in the S position for more than 5 seconds, then upshift to 3rd gear, and drive in 3rd gear for more than 5 seconds. Slow down and stop the wheels.

5.

Monitor the OBD status for P0842 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail. Does the result indicate FAILED? YES - Go to 6. NO - Intermittent failure, the system is OK at this time. Check the OP2SW (BLU/RED) wire for an intermittent short to ground between the 2nd clutch transmission fluid pressure switch and the PCM. If the tester indicates NOT COMPLETED, return to 4 and recheck.n

6.	Turn the ignition switch OFF.

7.	Disconnect the 2nd clutch transmission fluid pressure switch connector.

8.	Turn the ignition switch ON (II).

9.	Check the 2nd PRES SWITCH signal with the HDS in the A/T data list. Is the 2nd PRES SWITCH OFF? YES - Replace the 2nd clutch transmission fluid pressure switch, then go to 14. NO - Go to 10.

10.	Turn the ignition switch OFF.

11.	Jump the SCS line with the HDS.

12.	Disconnect PCM connector B (44P).

13.

Check for continuity between PCM connector terminal B8 and body ground.   Is there continuity? YES - Repair short to ground in the wire between PCM connector terminal B8 and the 2nd clutch transmission fluid pressure switch, then go to 14. NO - Update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck. If the symptom/indication goes away with a known-good PCM, replace the original  PCM.n

14.	Clear the DTC with the HDS.

15.	Start the engine, and warm it up to normal operating temperature (the radiator fan comes on).

16.	Drive the vehicle in 2nd gear in the S position for more than 5 seconds, then upshift to 3rd gear, and drive in 3rd gear for more than 5 seconds. Slow down and stop the wheels.

17.	Monitor the OBD status for P0842 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail. Does the result indicate PASSED? YES - Troubleshooting is complete.n NO - Return to 6 and recheck.