So I'm still getting this PO734 engine code every couple of weeks and I figured I would check my transmission fluid since I haven't looked at itsince changing it a few months ago. I unplugged the fill plug and about half a quart probably came gushingout. I assume this is because the fluid was still pretty warm (it had been sitting for about 1.5 hours in 30 deg weather since being driven) and it was cold when I had changed it. So, I forget, is it supposed to be checked when cold (it's about35 degrees out now) or when warm after being driven? Seems like every other tranny is checked when warm. I can't believe the owner's manual says nothing about checkingthe fluid.Could the fluid level even throw a code?

 

You are supposed to check and refill the tranny when the engine has been running for about 2 minutes, check it in park.
The 734 code has nothing to do with the fluid level, it is a 4th. gear out of ratio problem usually associated with a failing MAF.

 

Mike, I think that I read a post somewhere when you said that a weak battery could cause a fault in the ecu and give this code. Was that you, I can't remember? My battery reads only 12.3 volts, so maybe it could give a code if the battery drops low enough when cold and has a big draw on it?? My truck runs fine, it just gives the code every couple of weeks.

 

If tested properly, a battery/alternator should be 13.6 to 14.4, or you will have problems.

 

How do you test properly, just so I can see if I'm doing it right.
RM

 

Take it down to one of the local auto parts stores and have them do a free load test on both the alternator and battery.