Any interest in a Writeup for howto install an AW4 behind a 4.0L in a WJ?

I need to make a circuit that takes the signal from an XJ VSS in the t-case and turns it into a signal that sweeps from 0v to 5v between 0mph and 100mph so the WJ's PCM doesn't whine about the missing 42RE (all solenoids and the temp sensors have been dummied out with resistors and the speed sensor signal is just tied to the signal output from the ABS module.

ONLY code is p1762, and it comes and goes, if I fake the gov. pressure sensor signal a little better I know it'll go away.

physical install was mostly 91 XJ parts (tranny, tcu and harness and tranny mount), used 91 XJ flywheel first, ran like crap, swapped it for a 99 flywheel and it was fine, windows on the tone ring are VERY similar, off by millimeters, and it makes a HUUUUGE difference.

stock XJ transmission shifter cable was adapted at the center console shifter using a piece of an e32 BMW hood hinge.

V8 WJ brackets were used for the transfer case shifter cable (cable came from quadratrac 4.0L WJ) made a lever for the 242 t-case by shortening a quadratrac lever.

redrilled the crossmember to fit the XJ tranny mount and then just offset the tranny mount 1/2" toward the tranny pan (made a spacer so it overlaps, yes I know, gotta drop the crossmember to change the filter, but AW4 has a drain plug, so fukk it!)

this was both a 4wd swap and a tranny swap. 2wd tranny blew up after the new head went on (0331 garbage) so it rushed the project a little.

I have notes and I should publish them, if nothing else for when I go to the parts store and forget what part came from where! :wierd:

yes, i do have a power/comfort mode switch. it is awesome. It is just as good as the aw4 ZJ I did, if not better, definitely more time consuming than the ZJ swap, ZJ 42re had a separate TCU I could rip out, but I am so close to having the PCM completely fooled. I know the 42re can act stupid and slip and not throw the CEL, so as long as I fake it, I should be good!

That's what she said :laugh3:

but seriously, my roommate is delivering pizzas in it right now. I think he's more stoked about it than I am (he did most of the work anyway, I just did the R & D)



I've been wanting to see this happen since 2006.

WJ owners all over are going to LOVE this thread!

I say more info you can bring is awesome. I have a wj 2000 with a 4.0 and 178k on the clock. Have an extra 4.0 ready but was considering doing this if the tranny or t-case went out.

It would likely be easier using all OBDII stuff. I went for the 91 TCU because I wanted the dual program power/comfort modes. Things like the input/output speed sensors are directly compatible with the PCM. Again, I've got one trouble code to make go away and then I'll post the electrical notes. My roommate is putting together a narrative as well. I'll grab some pics of the electrical experimentation (currently there is a 42re-in-a-bag™ wired to the WJ pcm to make all the open circuit codes go away)

good work Ryan! looking forward to your finished results because i have one of those "southern" WJs without a t/case myself and 2nd gear is slipping so a swap is in my near future.

I am definitely interested, do they still use the same JTEC ECU that XJs and dodge trucks/vans use?

Because I've always daydreamed about taking a $500 dodge 2500 van with a blown up transmission, swapping an nv3500 or nv4500 manual into it, and using it as a tow rig. Hell, I started collecting parts for it when the trans blew up in my 01 2500, but ended up needing $500 more than I needed a rusty dented dodge van with a blown transmission.

I am pretty sure doing a manual swap would be roughly the same as an AW4 swap, at least as far as faking out the pressure sensor and solenoid codes. I got as far as realizing the PCM pulsewidth modulates the solenoid to shift an essentially hydraulic transmission via electronic control and realized I didn't care that much.

Great work, if I had to guess you could probably fake the pressure sensor return signal and possibly any speed sensors the PCM is expecting by measuring the pulse width of the solenoid drive signal and figuring out what gear the PCM wants the transmission to be in. I think that would probably eliminate all codes, but I never got as far as trying it.

I could physically connect a TJ PCM I'll have to look at wiring and see what everything does. I'd need a 4.0L 5-speed 2000 TJ w/ ABS. Does that even exist?

Not sure about the ABS, did TJs get that? I would worry more about PCI vs CCD vs CAN bus and having a BCM vs not having one... the WJs all used Teves mark 20 or 20e ABS HCUs that mostly managed their own business I thought.

What I meant is that if you can fake out the PCM into thinking it still has a 545rfe or 46re or whatever the WJ got, I am almost certain you could fake it out and put in an AX15 instead. Then you'd just need to figure out what to do about a clutch pedal.

Export diesel 5spd WJ? If so exist.

The factory parts catalog doesn't show one, I checked a while ago because a coworker of mine wishes hers was a standard.

5spd KJ parts then maybe.

You may be able to source parts from a zj with a 5 speed. My folks had a 94. Wish I bought it from them, was super fun to drive especially in the snow.

Of course it would probably just be easier to reflash the ECU with a manual transmission calibration and not have to worry about trying to trick it into thinking it has all of the AT sensors hooked up.

Sorry somewhat off topic, but is there a link to the ZJ AW4 swap?

adrenalinepirate said:

You may be able to source parts from a zj with a 5 speed. My folks had a 94. Wish I bought it from them, was super fun to drive especially in the snow.

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Good luck finding one, they made about 600 93s and 400 94s. 3 of them are in the local club I'm in, and apparently your parents had another, that leaves around 996 more for the rest of the country...

I don't there are even openings in the firewall on the WJ, so you'd have to basically start from scratch and custom fab the whole thing unless something magically lines up due to design commonalities and they just never set the WJ up for it.

XJPaul said:

Sorry somewhat off topic, but is there a link to the ZJ AW4 swap?

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I never did a writeup on that because it was a 95, early 93s had aw4s and I just duplicated that, all the info is in the service manual or on alldata