Acura TL code P0700, code P0847

2004 Acura TL Base 3.2L, V6, MFI, SOHC, Eng Desg J32A3

Problem: Automatic transmission malfunction code P0700 is set. The D light will flash. 3rd clutch transmission fluid pressure switch code P0847 is set. Freeze frame data showed all three shift solenoids were off (4th gear) when the code set. The transmission shifts fine.

Tests: 
1. Backprobe and check the voltage for the 3rd clutch transmission fluid pressure switch on the Blue/White wire, at the 3rd clutch transmission fluid pressure switch, or on the Blue/White wire at terminal C5 at the PCM. The PCM sends out a 5.0 volt reference to the 3rd clutch transmission fluid pressure switch and the 3rd clutch transmission fluid pressure switch closes to ground (near 0 volts on the Blue/White wire) when there is 3rd clutch pressure. There should be 3rd clutch pressure when the transmission is in 3rd gear. There should be approximately 5.0 volts on the Blue/White wire when there is no 3rd clutch pressure - not in 3rd gear.

2. Backprobe and check the voltage for the 4th clutch transmission fluid pressure switch on the Blue/Yellow wire at the 4th clutch transmission fluid pressure switch or on the Blue/Yellow wire at terminal C13 at the PCM to see how it responds since the code set with the transmission in 4th gear. The PCM sends out a 5.0 volt reference to the 4th clutch transmission fluid pressure switch and the 4th clutch transmission fluid pressure switch closes to ground (near 0 volts on the Blue/Yellow wire) when there is 4th clutch pressure. There should be 4th clutch pressure when the transmission is in 4th gear. There should be approximately 5.0 volts on the Blue/Yellow wire when there is no 4th clutch pressure - not in 4th gear.

Potential Causes:  3rd Clutch Transmission Fluid Pressure Switch
Automatic Transmission

Confirmed Fix: Replaced 3rd Clutch Transmission Fluid Pressure Switch: Replaced both the 3rd clutch transmission fluid pressure switch and the 4th clutch transmission fluid pressure switch. The dealer had several in stock.
Replaced 4th Clutch Transmission Fluid Pressure Switch

Tech Tips: Trouble code P0700 in the Powertrain Control Module (PCM) just indicates there is a malfunction in the transmission. Need to check transmission codes to determine what the transmission malfunction is. Since freeze frame data showed all three shift solenoids were off (4th gear) when the code set, maybe the 3rd clutch transmission fluid pressure switch was still ON in 4th gear. Since the transmission shifts fine, it is more likely a defective 3rd clutch transmission fluid pressure switch.