I wish my 1996 had those 2 diagnostic boxes. Pull the lid off of A and stick the probe into 1 (tranny). Turn the key to posII and close the door. Press the little black button once (just a blip) and wait for the 3 numbered code to flash. Press again to get the next code, etc., until you get the first one again. Now is a good time to erase them, assuming you wrote them all down, press the button for 5-7 seconds, wait for the red light, press again for 5-7 seconds, and they should clear. Remember some of the codes might be 'old', so you want to check the codes again.

Repeat for A2 and A6. The B box is for SRS, seats, other junk.

Ffirst, check the ATF for color and level. I prefer to check with a cold engine and tranny. The dipstick is under the air intake on the driver's side. Flushing is a 30 minute job in your garage, many write ups here.

Before you 'repair' a tranny, look into getting one from a salvage yard. 1994-5 will be a drop in, 1996 and newer require some rewiring. If yours is not slipping, it could be a clogged solenoid or a bad PNP switch. Is the arrow flashing? Row the shift lever from R to L about 20 times and try again.