Electrical AW4 issue after motor swap

Ok guys, I have been reading all the AW4 threads and how to adjust it and how to check the solenoids. However, I dont think any of these are my issues so before I go and screw something else up I figured I would tell you what I have done......


Jeep is a 2000 XJ with 4.0 and Aw4 4x4 (2wd hi,4x4 hi,N,4x4 low) Np231 I assume.

Donor motor 4.0 pulled out of my wrecked 2001 (100,338 miles). Cleaned it and painted the block. Left the flywheel and torque converter on it (part numbers were the same from 01 and 00).

Disconnected everything and Removed the 4.0 in the 2000 XJ I bought (217K miles) that the owner told me needed a motor due to the head being cracked, washed the engine bay and installed the 2001 motor into the 2000. Used the TB off the 2000 motor as the 2001 TB idled real low so it was easier to swap TB's instead of all the sensors.

Jeep idles great, runs good, but when I test drove the jeep it seems that on normal cruising it stays in gear and runs up higher than normal into the RPMs but if I slightly let off the gas pedal it will shift up. Manually shifting the selector seemed not to make any changes.

Thanks to kastein on here I unplugged the gray harness near the dip stick, drove it in manual mode shifting up and down, and it drives and shifts as it should unplugged.

So now my question is the jeep drove/shifted fine before the motor swap so I assume I have a bad connection or bad ground as it seems to be a electrical issue. I have searched for a diagram but did not find one. So what connections grounds should I check or is there something I might be over looking?

Transmission wiring connections I know I unplugged:
1. Gray Plug at the oil dip stick and the black ones.
2. Grounds on the side of the motor above the oil dipstick
3. Two plugs on the transmission (one is crank sensor - other not sure)
4. Grounds on motor between alt and motor mount

And I did remove the transmission shifter cable but it went right back in the right position and selector shows all the right positions.

Im assuming I have a bad plug connection, a bad ground, or I'm over looking a plug undone somewhere. I'm not a automatic person so all of this is new to me.


Any help or idea's I can check would be appreciated.
Thanks

We need a better detail list of what changed about the shifting I think.

The TPS can affect shifting, as can the setting on the transmission cable that is attached to the throttle (I forget its name shift cable, knock down cable?). Have you read these threads?

http://www.naxja.org/forum/showthread.php?t=1053970

http://www.naxja.org/forum/showthread.php?t=980850

Ecomike said:

We need a better detail list of what changed about the shifting I think.

The TPS can affect shifting, as can the setting on the transmission cable that is attached to the throttle (I forget its name shift cable, knock down cable?). Have you read these threads?

http://www.naxja.org/forum/showthread.php?t=1053970

http://www.naxja.org/forum/showthread.php?t=980850

Click to expand...

Read them both and am assuming its not related to my issue.
The jeep ran and drove fine before the motor swap (swapped motors due to cracked head and low oil pressure). New used motor in the jeep and runs like it did before the swap with great oil pressure.
Once I drove it on a test drive the trans did not want to shift and ran up to 4-5k, once I let off the pedal it then would shift.
I dont have any codes being thrown, nor was I having issues with shifting or running before so its more like I have not plugged something up or have a bad connection or ground as in manual mode it shifts fine.

Have not drove it more as I dont want to mess anything up.
I have not adjusted or changed any parts that would effect the electronics so really dont want to start adjusting until I know for sure.

The TPS cannot be adjusted on 91 and later - a blessing and a curse.

Wait, you unplugged the grey connector? That's the NSS, the solenoid drive and ISS/OSS sensor signal cable is the black one. I hope I didn't tell you it was the grey one in our conversation a few days ago :dunce:

01yellowxj said:

Read them both and am assuming its not related to my issue.

Click to expand...

My apologies, I posted the wrong link on one of those, cable adjustment thread, it is:

http://www.naxja.org/forum/showthread.php?t=1015963&highlight=aw4+cable+adjustment

But why would you assume that for the other thread, the "all you wanted to know about AW4 thread" when your problem is a shifting problem with the AW4?

kastein said:

The TPS cannot be adjusted on 91 and later - a blessing and a curse.

Wait, you unplugged the grey connector? That's the NSS, the solenoid drive and ISS/OSS sensor signal cable is the black one. I hope I didn't tell you it was the grey one in our conversation a few days ago :dunce:

Click to expand...

No, sorry. I did unplug the black harness plug as you told me.

Ecomike said:

But why would you assume that for the other thread, the "all you wanted to know about AW4 thread" when your problem is a shifting problem with the AW4?

Click to expand...

I got into several pages talking about what you can and cannot swap and what the different years consist of. Its a great thread but I feel my issue is a connection somewhere so i would like to know the wiring diagram or all the connections / grounds related to the 2000/2001 AW4 wiring so I could trouble shoot if mine is for sure a connection issue.

There is a ground point for the Transmission Control Module on the right side of the engine, near the alternator. Two studs. The battery, PCM, O2S heaters, and TC light switch also ground here. Make sure all wires are securely fastened here.

The Transmission Range Sensor (NSS) is grounded on the left fender liner, near the air filter box and the PCM. Two bolts. There's many circuits here and it's doubtful there's any problem at this ground point...just a FYI.

Sidewinder CC said:

There is a ground point for the Transmission Control Module on the right side of the engine, near the alternator. Two studs. The battery, PCM, O2S heaters, and TC light switch also ground here. Make sure all wires are securely fastened here.

The Transmission Range Sensor (NSS) is grounded on the left fender liner, near the air filter box and the PCM. Two bolts. There's many circuits here and it's doubtful there's any problem at this ground point...just a FYI.

Click to expand...

Thanks, so that than those, the black plug at the dipstick there are no other connectors expect the ones on the trans or bolted to the trans.
Is that a safe bet? Asking as I plan to take it to the fire house sunday when I work and plan to clean all the connections. Maybe when I power washed the engine compartment I got junk in one or when I painted the block Im not getting a good ground.

And yes, I never did touch the grounds near the PCM so thats probably not it but will clean them if the others dont work.

When you swapped the engines you need to re-adjust the TV cable that connects to the throttle so the transmission shifts properly. The transmission itself uses the TV cable to set the hydraulic pressure vs throttle position, and the TCU (transmission control unit) electrically looks at the TPS (throttle position sensor) to command the transmission solenoids. Both the TV cable and the TPS need to be properly set/working properly for the transmission to shift properly.

The instructions for setting the TV cable appear many places -- here's one:
http://naxja.org/forum/showpost.php?p=244675010&postcount=1

HTH

OK, so maybe were getting somewhere......

I didn't think that if Im using the same intake manifold with the same TV cable and the TPS I did not have to adjust them but its making since.

Again, this is the reason im asking because this is my 1st time having to work on my XJ other than tune up items, brakes, axles.

I am planning to take it to work tomorrow, I will double check all connections are clean and then read into the two adjustments and perform them since I can use the heated bay at the station.


Thanks for all the help guys I do appreciate it.

Adjusting the TV cable is super easy - I think it took me more time to get my hood open than adjusting it took.

Adjusting the TPS is impossible on a 91 or later jeep, so no worries there. If you have an analog voltmeter around, it might pay to check the TPS linearity with the key on but the engine not started... if it's not a smooth voltage change as you open the throttle slowly, you may be due for a new one.

Ok, ran out in the snow and adjusted the TV cable after I plugged the black connector back for the Tranny electronics.
Drove the jeep and it shifts normal, a bit harder than normal but seems to fix the issue.
The only thing now is I cant get to WOT due to the TV cable not coming out.

readjusted and WOT is fixed.


1. Open hood with motor off
2. Push button on cable and pushed all the way in
3. Still holding the button rotated the throttle to wide open, released button.
4. Released the throttle and closed the hood
5. Test drove and jeep is all good

FTW not many people remember to adjust the NSS correctly--it provides feedback to the TCU on the manual position of the shifter and can cause issues beyond not starting in Park or Neutral.

joe_peters said:

FTW not many people remember to adjust the NSS correctly--it provides feedback to the TCU on the manual position of the shifter and can cause issues beyond not starting in Park or Neutral.

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ya, crazy thing is one would think if you did not swap any electronics and only used the block that all the electronics would stay in the same setting.

Good thing is the two weeks of issues and it was a simple 1min fix and I get to drive the jeep today to work so I know I will make it in the snow/ice we got yesterday/last night.