Acura RL. Manual - part 254

and the PCM, then go to step 1. If the HDS indicates NOT COMPLETED, return to step 18 and recheck.

DTC P0872: Short in 4th Clutch Transmission Fluid Pressure Switch Circuit, or 4th Clutch Transmission Fluid 
Pressure Switch Stuck ON 

1. Clear the DTC with the HDS.  

2. Check the 4th PRESSURE SWITCH signal with the HDS in the A/T data list when not in 4th gear. 

Is the 4th PRESSURE SWITCH OFF?  

YES - Go to step 3. 

NO - Go to step 6. 

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

4. Test-drive the vehicle in 5th gear in M for at least 2 seconds, then slow down to a stop.  

5. Monitor the OBD STATUS for P0872 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail. 

Does the HDS indicate FAILED?  

YES - Go to step 6. 

NO - Intermittent failure, the system is OK at this time. Check the 0P4SW wire for an intermittent short 
between the 4th clutch transmission fluid pressure switch and the PCM. If the HDS indicates NOT 
COMPLETED, return to step 

4

 and recheck. 

6. Turn the ignition switch to LOCK (0).  

7. Disconnect the 4th clutch transmission fluid pressure switch connector.  

8. Turn the ignition switch to ON (II).  

9. Check the 4th PRESSURE SWITCH signal with the HDS in the A/T data list. 

Is the 4th PRESSURE SWITCH OFF?  

YES - Replace the 4th clutch transmission fluid pressure switch (see 4TH CLUTCH TRANSMISSION 
FLUID PRESSURE SWITCH REPLACEMENT ), then go to step 11. 

NO - Go to step 10. 

NOTE:



Before you troubleshoot, record all freeze data and any on-board 
snapshot, and review General Troubleshooting Information (see GENERAL 
TROUBLESHOOTING INFORMATION ).  



This code is caused by an electrical circuit problem and cannot be caused 
by a mechanical problem in the transmission.  

 

2007 Acura RL 

2005-08 TRANSMISSION Automatic Transmission - RL

  

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10. Turn the ignition switch to LOCK (0).  

11. Jump the SCS line with the HDS.  

12. Disconnect PCM connector C (22P).  

13. Check for continuity between PCM connector terminal C20 and body ground. 

Fig. 131: Checking Continuity Between PCM Connector Terminal C20 And Body Ground 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

Is there continuity?  

YES - Repair short in the wire between PCM connector terminal C20 and the 4th clutch transmission 
fluid pressure switch, then go to step 19. 

NO - Go to step 14. 

14. Reconnect all connectors.  

15. Update the A/T software in the PCM if it does not have the latest software (see UPDATING THE 

PCM ), or substitute a known-good PCM (see SUBSTITUTING THE PCM ).  

16. Test-drive the vehicle in 4th gear in M for at least 2 seconds, then upshift to 5th gear, and drive in 5th 

gear for at least 2 seconds. Slow down and stop the wheels.  

17. Check for DTC(s) in the DTCs/Freeze Data in A/T Mode Menu with the HDS. 

Is DTC P0872 indicated?  

YES - If the PCM was updated, substitute a known-good PCM (see SUBSTITUTING THE PCM ), 
then recheck. If the PCM was substituted, go to step 1. 

NO - Go to step 18. 

18. Monitor the OBD STATUS for P0872 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail. 

Does the HDS indicate PASSED?  

YES - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the 

 

2007 Acura RL 

2005-08 TRANSMISSION Automatic Transmission - RL

  

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© 2005 Mitchell Repair Information Company, LLC. 

original PCM (see PCM REPLACEMENT ). If any other DTCs were indicated on step 17, go to the 
INDICATED DTCS TROUBLESHOOTING. 

NO - Check for poor connections and loose terminals at the 4th clutch transmission fluid pressure switch 
and the PCM. If the PCM was updated, substitute a known-good PCM (see SUBSTITUTING THE 
PCM ), then recheck. If the PCM was substituted, go to step 1. If the HDS indicates NOT COMPLETED, 
return to step 16 and recheck. 

19. Clear the DTC with the HDS.  

20. Test-drive the vehicle in 4th gear in M for at least 2 seconds, then upshift to 5th gear, and drive in 5th 

gear for at least 2 seconds. Slow down and stop the wheels.  

21. Check for DTC(s) in the DTCs/Freeze Data in A/T Mode Menu with the HDS. 

Is DTC P0872 indicated?  

YES - Check for poor connections and loose terminals at the 4th clutch transmission fluid pressure switch 
and the PCM, then go to step 1. 

NO - Go to step 22. 

22. Monitor the OBD STATUS for P0872 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail. 

Does the HDS indicate PASSED?  

YES - Troubleshooting is complete. If any other DTCs were indicated on step 21, go to the INDICATED 
DTCS TROUBLESHOOTING. 

NO - Check for poor connections and loose terminals at the 4th clutch transmission fluid pressure switch 
and the PCM, then go to step 1. If the HDS indicates NOT COMPLETED, return to step 20 and recheck. 

DTC P0873: Open in 4th Clutch Transmission Fluid Pressure Switch Circuit, or 4th Clutch Transmission Fluid 
Pressure Switch Stuck OFF 

1. Clear the DTC with the HDS.  

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

3. Test-drive the vehicle in 4th gear in M, and verify with the HDS in the A/T data list that the SHIFT 

COMMAND indicates 4th.  

4. Check the 4th PRESSURE SWITCH signal with the HDS in the A/T data list. 

NOTE:



Before you troubleshoot, record all freeze data and any on-board 
snapshot, and review General Troubleshooting Information (see GENERAL 
TROUBLESHOOTING INFORMATION ).  



This code is caused by an electrical circuit problem and cannot be caused 
by a mechanical problem in the transmission.  

 

2007 Acura RL 

2005-08 TRANSMISSION Automatic Transmission - RL

  

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© 2005 Mitchell Repair Information Company, LLC. 

Is the 4th PRESSURE SWITCH ON? 

YES - Go to step 5. 

NO - Go to step 7. 

5. Test-drive the vehicle in 4th gear in M for at least 2 seconds, then slow down to a stop.  

6. Monitor the OBD STATUS for P0873 in the DTCs/Freeze Data in A/T Mode Menu for a pass/fail. 

Does the HDS indicate FAILED?  

YES - Go to step 7. 

NO - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at 
the 4th clutch transmission fluid pressure switch and the PCM. If the HDS indicates NOT COMPLETED, 
return to step 5 and recheck. 

7. Turn the ignition switch to LOCK (0).  

8. Disconnect the 4th clutch transmission fluid pressure switch connector.  

9. Turn the ignition switch to ON (II).  

10. Measure the voltage between the 4th clutch transmission fluid pressure switch connector terminal and 

body ground. 

Fig. 132: Measuring Voltage Between 4th Clutch Transmission Fluid Pressure Switch Connector 
Terminal And Body Ground 
Courtesy of AMERICAN HONDA MOTOR CO., INC. 

Is there about 5 V?  

YES - Replace the 4th clutch transmission fluid pressure switch (see 4TH CLUTCH TRANSMISSION 
FLUID PRESSURE SWITCH REPLACEMENT ), then go to step 17. 

NO - Go to step 11. 

11. Measure the voltage between PCM connector terminal C20 and body ground. 

 

2007 Acura RL 

2005-08 TRANSMISSION Automatic Transmission - RL

  

me 

 

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© 2005 Mitchell Repair Information Company, LLC.