Ok so my auto aw4 trans started slipping when cool then would be fine until yesterday it went all to **** on me. Started out fine the. Was slipping in 3rd wouldn't upshift. Then it started delaying shifts and kept upshifting and downshifting back and forth I have no clue what it could be any help would be greatly appreciated. 89 cherokee 250k miles

 

First off, check the fluid level. I'm not too familiar with the renix years, but I think that one still has a throttle cable going to the transmission that you have to adjust, so check the adjustment on that.

If it truly is slipping, then it might just be time for another transmission...

 

fluid is fine did the cable adjustment. Im thinking its something electronic bad but still not sure

 

CRUISER'S MOSTLY RENIX TIPS

RENIX GROUND REFRESHING

OCTOBER 30, 2015 SALAD 77 COMMENTS

The Renix era XJs and MJs were built with an under-engineered grounding system for the engine/transmission electronics. One problem in particular involves the multiple ground connection at the engine dipstick tube stud. A poor ground here can cause a multitude of driveabililty issues, wasted time, failed emission tests, and wasted money replacing components unnecessarily.

All the components listed below ground at the dipstick tube stud:

Distributor Sync Sensor, TCU main ground, TCU “Shift Point Logic”, Ignition Control Module, Fuel Injectors, ECU main ground (which other engine sensors ground through, including the Oxygen sensor, Knock Sensor, Cruise Control and Transmission Sync signal. All extremely important stuff.

The factory was aware of the issues with this ground point and addressed it by suggesting the following:

• Remove the nut holding the wire terminals to the stud. Verify that the stud is indeed tightened securely into the block. If the whole stud turns, you can use a 7/32″ six point socket or wrench to hold it so the nut can be removed. Worst case, cut the wires and remove the stud and nut. Install new terminal eyelets on the wires when going back together. Scrape any and all paint from the stud’s mounting surface where the wires will attach. Surfaces must be clean, shiny and free of any oil, grease, or paint.
• Inspect the wire terminals. Check to see that none of the terminals are crimped over wire insulation instead of bare wire. Be sure the crimps are tight. It wouldn’t hurt to re-crimp them just as a matter of course. Sand and polish the wire terminals until clean and shiny on both sides. Apply a liberal coating of
  OxGard
  OxGard
  , which is available at Lowe’s and other stores. Reinstall all the wires to the stud and tighten thhttps://i0.wp.com/cruiser54.com/wp-content/uploads/2015/10/dipstick-stud.jpge nut down securely.

While you’re in that general area, locate the battery negative cable which is fastened to the engine block just forward of the dipstick stud. Remove the bolt, scrape the block to bare metal, clean and polish the cable terminal, apply , and reattach securely.

Another area where the grounding system on Renix era Jeeps was lacking is the engine to chassis ground. There is a braided cable from the back of the cylinder head that also attaches to the driver’s side of the firewall. This cable is undersized for its intended use and subject to corrosion and poor connections at each end.

• Remove the cable end from the firewall using a 15mm wrench or socket. Scrape the paint off down to bare metal and clean the wire terminal. Apply
  OxGard
  OxGard
  . Reattach securely.
• Remove the other end of the cable from the rear of the head using a 3’4″ socket. Clean all the oil, paint and crud from the stud. Clean the wire terminal of the cable and reattach securely with a liberal coating of
  OxGard
  OxGard
  .

2 STRONG suggestions regarding the ground system:

I prefer to add a #4 gauge cable from the firewall to a bolt on the rear of the intake manifold, either to a heat shield bolt or fuel rail bolt. A cable about 18″ long with a 3/8″ lug on each end works great and you can get one at any parts store already made up. NAPA has them as part number 781116.

A further improvement to the grounding system can be made using a #4 cable, about 10″ long with 3/8″ terminals at each end. Attach one end of this cable to the negative battery bolt and the other end under the closest 10mm headed bolt on the radiator support just forward of the battery. NAPA part number 781115.

For those of us with Comanches, it’s very important to remove the driver’s side tail lamp assembly to access the ground for the fuel pump. Remove the screw holding the black ground wire. Scrape the paint from the body and corrosion from the wire terminal. Add a 10 gauge wire, with an eyelet on each end, from that grounding point to a bolt on the frame. Better yet, on both Cherokees and Comanches, complete Tip 29 for the best fuel pump grounding. Be sure to scrape all mounting points to bare metal and apply also.https://i0.wp.com/cruiser54.com/wp-content/uploads/2015/10/Fuel-Pump-Ground-Comanche.jpg
If you want to UPGRADE YOUR GROUND AND BATTERY CABLES with custom made parts, contact Paul at www.jeepcables.com

 

CRUISER'S MOSTLY RENIX TIPS

TRANSMISSION CONNECTOR REFRESHING

OCTOBER 30, 2015 SALAD 24 COMMENTS



Over near the transmission dipstick tube are 2 rather large connectors. One is black and goes to the NSS and the gray connector goes to the transmission itself
. These 2 connectors carry all the info between TPS, TCU, NSS, speed sensor, and transmission solenoids.

Unplug each one, visually inspect for corrosion or bent pins, spray them out with electrical contact cleaner and plug them back in.

Additionally, if your Jeep is an ’87 to ’90 Renix, it’s always a good idea to reach up under the glovebox area and unplug the connector to the TCU and spray it out along with the receptacle of the TCU. While you’re there, find the fuse right in that area for the TCU. Remove it and spray out it’s receptacle and clean any corrosion from the fuse.

 

I've checked the grounds they all seem fine. I'll check the connectors today and see if that helps any. Thank you and I'll update soon as I get a chance

 

"checked" and "seem"?

 

I put a meter on and was getting continuity on all spots i checked so thats why i said they all seemed to be fine nothing broken or corroded

 

Okay. Cool. Just making sure.

Tip 10 would be next then.

BTW, whwn you adjusted the TV cable, did it end up in a different spot than it was in before?

 

it may have moved like a 1/8 inch. What was tip 10 again? Sorry believe I missed something

 

Post #6

 

gotcha

 

Try pull your TCU fuse and drive it using the shifter in 1-2 for 1st, 3 for 3rd and D for 4th, that will remove all electrical control of the AW4. If it all behaves, it's going to be electrical, if it still acts up, mechanical.

 

thanks I'll try that as well

 

ok so I pulled the fuse and drove it around a little not far. Never really hit 2nd but just a fraction of a second when I Shifted into 3rd not sure if that's normal but I guess it is since 1 and 2 are in the same location and I assume that part is controlled electrically. All in all it Shifted fine through all gears up and down. So does that mean either tps or tcu? Also inspected the wiring crusier mentioned to look at they all seem fine as well