DTC P0847: Transmission Fluid Pressure Switch B (3rd Clutch) (Short or Stuck ON)
- Before you troubleshoot, record all freeze data and any on-board snapshot with the HDS, 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.
- Some wire colors vary according to the model year, and are indicated with an asterisk as follows:
- *(1): '09 - 10 models
- *(2): '11 - 12 models
- Clear the DTC with the HDS.
- Check the 3rd Pressure Switch signal with the HDS in the A/T data list when not in 3rd gear.
Is the 3rd Pressure Switch OFF?
YES -Go to step 3.
NO -Go to step 6.
- Start the engine, and warm it up to normal operating temperature (the radiator fan comes on).
- Test-drive the vehicle:
- Seven-position transmission: Drive the vehicle in 4th gear in D for at least 2 seconds, then slow down to a stop.
- Five-position transmission: Drive the vehicle in 4th gear in the sequential sportshift mode in S for at least 2 seconds, then slow down to a stop.
- Monitor the OBD status for P0847 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 OP3SW wire for an intermittent short to ground between the transmission fluid pressure switch B (3rd clutch) and the PCM. If the HDS indicates NOT COMPLETED, return to step 4 and recheck.
- Turn the ignition switch to LOCK (0).
- Disconnect the transmission fluid pressure switch B (3rd clutch) connector.
- Turn the ignition switch to ON (II).
- Check the 3rd Pressure Switch signal with the HDS in the A/T data list.
Is the 3rd Pressure Switch OFF?
YES -Replace the transmission fluid pressure switch B (3rd clutch) (see TRANSMISSION FLUID PRESSURE SWITCH B (3RD CLUTCH) REPLACEMENT ), then go to step 20.
NO -Go to step 10.
- Turn the ignition switch to LOCK (0).
- Jump the SCS line with the HDS.
- Disconnect PCM connector B (49P).
- Check for continuity between PCM connector terminal B9 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Repair a short in the wire between PCM connector terminal B9 and the transmission fluid pressure switch B (3rd clutch), then go to step 20.
NO -Go to step 14.
- Reconnect all connectors.
- Update the A/T software in the PCM if it does not have the latest software (see ECM/PCM UPDATE ), or substitute a known-good PCM (see SUBSTITUTING THE ECM/PCM ).
- Start the engine, and warm it up to normal operating temperature (the radiator fan comes on).
- Test-drive the vehicle:
- Seven-position transmission: Drive the vehicle in 3rd gear in D for at least 2 seconds, then press the accelerator pedal so that the transmission upshifts into 4th gear, and drive in 4th gear for at least 2 seconds. Slow down and stop the engine.
- Five-position transmission: Drive the vehicle in 3rd gear in the sequential sportshift mode in S for at least 2 seconds, then upshift to 4th gear by pulling the paddle shifter + (upshift switch), and drive in 4th gear for at least 2 seconds. Slow down and stop the engine.
- Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0847 indicated?
YES -If the PCM was updated, substitute a known-good PCM (see SUBSTITUTING THE ECM/PCM ), then recheck. If the PCM was substituted, go to step 1.
NO -Go to step 19.
- Monitor the OBD status for P0847 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 original PCM (see ECM/PCM REPLACEMENT ). If any other DTCs were indicated on step 18, go to the indicated DTC's troubleshooting.
NO -Check for an intermittent short in the wire between the transmission fluid pressure switch B (3rd clutch) and the PCM. If the PCM was updated, substitute a known-good PCM (see SUBSTITUTING THE ECM/PCM ), then recheck. If the PCM was substituted, go to step 1. If the HDS indicates NOT COMPLETED, return to step 17 and recheck.
- Reconnect all connectors.
- Clear the DTC with the HDS.
- Start the engine, and warm it up to normal operating temperature (the radiator fan comes on).
- Test-drive the vehicle:
- Seven-position transmission: Drive the vehicle in 3rd gear in D for at least 2 seconds, then press the accelerator pedal so that the transmission upshifts into 4th gear, and drive in 4th gear for at least 2 seconds. Slow down and stop the engine.
- Five-position transmission: Drive the vehicle in 3rd gear in the sequential sportshift mode in S for at least 2 seconds, then upshift to 4th gear by pulling the paddle shifter + (upshift switch), and drive in 4th gear for at least 2 seconds. Slow down and stop the engine.
- Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0847 indicated?
YES -Check for an intermittent short in the wire between the transmission fluid pressure switch B (3rd clutch) and the PCM, then go to step 1.
NO -Go to step 25.
- Monitor the OBD status for P0847 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 24, go to the indicated DTC's troubleshooting.
NO -Check for an intermittent short in the wire between the transmission fluid pressure switch B (3rd clutch) and the PCM, then go to step 1. If the HDS indicates NOT COMPLETED, return to step 23 and recheck.