AW-4, error codes P0700, P0751

Well, I've just bought a 98 Cherokee sport with a 4 liters engine, and AW-4 with NP231.
After bringing it home, a engine check has been lighten up. With a scanner I've obtained the following codes:
- P0700 (EATX Controller DTC Present), which as far as I understand just states that Asin controller has an active fault.
The second one is P0751 (O/D Switch Pressed (LO) More Than 5 Minutes). Most of the time it drives smoothly. The trannie kicks occur very seldom, and mostly when it is cold. After 10-20 minutes of driving everything runs more or less ok.
So my question is: what does it mean? How severe is it? And what should I do at first?

P.S. Sorry for my English, it is not my first language.

Welcome, and do not worry, your English is very good.

If you use Google or some other search you can find the AW-4 Service Manual with all the necessary testing and service instructions. You might also find what you need in a genuine Jeep Service Manual from www.pacificcoastmanuals.com for only $7.95 (US).

Be sure to only use Dexron-III/Mercon transmission fluid in your AW-4.


I wish you good luck with the Jeep, maybe this will get you started on the dignostics.


P0751 JEEP - Over Drive Switch Pressed Low

Possible causes
•Faulty overdrive off switch
•Overdrive off switch harness or connectors
•Overdrive off switch circuit is open or shorted

When is the code detected?

The P0751 code is detected when the Over Drive (O/D) switch value has not changed for over 5 minutes

Thanks man for the info. I've already found the service manual, and now try to get the AW-4 book.

The code was detected "as usual" when I've bought the car and have driven away for about 200 miles.

Here's a recent update. I've changed the oil and both errors disappeared for now. (have driven about 70 miles). But noticed the following - while driving it shifts smoothly and in general the driving is ok. But when I'm standing still (with the brakes pressed) and shift gears from parking to reverse and from reverse to drive I hear the mechanical sound of gears engaging. It is not loud but very distinct. The same time the car makes slight kick forward or astern depending upon the gear selected. All this gear switching thing has begun before the oil change. So I'm thinking, Is the transmission slowly dying and it is time to go the qualified mechanic in a major city 500 miles away? Or it is ok for 21 years old transmission?

There is no OD switch on the Cherokee. P0751 means "Shift Solenoid A CKT performance or Stuck Off". Your description of the shifting sounds normal to me and I would not worry about it. If it is not shifting correctly, or is trying to start in 4th gear, then you may need to replace the solenoid. This can be done without removing the transmission from the vehicle by removing the oil pan. The AW4 transmission is strong transmission and most of the time the problem is electrical.

Почтальон;246633720 said:

d the following - while driving it shifts smoothly and in general the driving is ok. But when I'm standing still (with the brakes pressed) and shift gears from parking to reverse and from reverse to drive I hear the mechanical sound of gears engaging. It is not loud but very distinct.

Click to expand...

Hearing a small clunk, when shifting from drive to reverse, is normal, it's the slop or looseness in the drivetrain, mostly in the rear axle and driveshaft's slip joint .
Check the driveshaft's U-joints and hardware for looseness and wear..