AW4 delayed upshifts?

[scguy]

My AW4 is a 93 XJ unit, but running complete drivetrain, harness, computers etc from the same XJ. 

 

I'm finding the shift patterns very annoying. When it shifts, it's not a soft or slipping shift, it just seems like it wants to hang out in lower gears at all times, or downshift at a gnat's fart. At about 1/3 throttle, it will go up to about 3k RPM, and hold, I have to back off the pedal a bit to get it to upshift. 1/2 shift is somewhat this way, the 2/3 shift is definitely the most reluctant. 

 

I tried adjusting the transmission cable many times according to the procedure, no dice. I thought maybe it was just underpowered with the stock gearing, but now with the 4.56s, it's not much better. 

 

Fluid is clean and full. Any ideas? Is it worth it for the Transgo shift kit? Or should I just buy a Nifty Shifter?

 

 

[Strokermjcomanche]

Check your TPS and ohm your transmission solenoids to see if they are within range . 

[89 MJ]

Are you using an old transmission cooler? I'd make sure that isn't plugged. How long did the XJ sit? It could be possible that the transmission is all varnished up now and it needs to be flushed.

[scguy]

I drained and filled the AW4 with fresh fluid already. It does seem to get a bit better when it warms up. I'm currently using the cooler in my 3 row alum rad.

[scguy]

32 minutes ago, Strokermjcomanche said:

Check your TPS and ohm your transmission solenoids to see if they are within range . 

Thank you. I'll give that a shot

[75sv1]

I'd check your battery voltage. I'd check the ohms on the Solenoids. I have installed the Transgo kits. Both the basic and the advanced. Still, I could not give advice if they made a difference. I had other issues. Mine was the speed sensor on a '98. It has two. Yours should have one. I think there are 5 things that control the AW4. 

Solenoids, speed sensor, TPS, Range selector, Trans computer, Engine computer (EMS??), brake light switch. 

[scguy]

Battery voltage is pretty steady at 14.1V  

 

My speedometer is reading fairly high now after regearing. From the charts I've found, I need a 40 tooth speed sensor gear. Any places that have them for less than $40? Could the incorrect speed sensor gear cause issues?

[75sv1]

17 minutes ago, scguy said:

Battery voltage is pretty steady at 14.1V  

 

My speedometer is reading fairly high now after regearing. From the charts I've found, I need a 40 tooth speed sensor gear. Any places that have them for less than $40? Could the incorrect speed sensor gear cause issues?

I don't think it will solve the problem. Also, that's a different speed sensor. Although, I am no 'expert' on the AW4 or the earlier ones. The latter ones 98+ have two on the side. I think the earlier ones have one. 

 

Not sure if this is what I am talking about. The '98+ is different. 

[gogmorgo]

I’ve been weirded out the odd time by the power/comfort switch getting flipped without my noticing it and everything changes compared to what I was expecting. I’ve also had similar things happen when the fluid was still cold, to the point where it even hangs between gears for a couple seconds. We’re talking pushing -40 and not letting it warm up though, but then I’ve still got the stock heat exchanger in the rad without any additional cooling so I don’t know how it would behave in the cold otherwise. Or how cold it’s been where you are.

I’ll also second investigating the TPS. The first signs of it going out for me with the AW4 were that the truck started shifting like I was at wide open throttle.

[cruiser54]

In the swap, was anything done with the TCU by chance? 

The plug on the TCU harness must be the same color as the plug on the TCU.

 

Also, the ground for the TCU must be real good. 

 

Here's something else to check.

 

CRUISER'S MOSTLY RENIX TIPS

TRANSMISSION CONNECTOR REFRESHING

OCTOBER 30, 2015 SALAD 22 COMMENTS EDIT

 

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.

Revised 1-31-2016

[scguy]

During the swap, I carried over the TCU, harness and transmission all from the same vehicle. I'll double check all my grounds but I made sure to clean all grounding points when I went in. Haven't had time to check any of this yet, I live half a mile from work so it almost never has time to get up to temp, even after warming up by remote start these mornings, my rad temp is ~95F by the time I get to work

[scguy]

Hooked up the $12k Snappy scanner today to watch the trans data. It's about what I was thinking, when it was delaying shifts, the solenoids are not being commanded. The speed sensor is reading fine, my issue must with the TPS. 

 

The scanner reports TPS in 8 steps, 0-7. Closed throttle reads 0, but it ramps very fast to 4 and 5, I'm talking about maybe 15-20% throttle. It goes through 1-4 in less than 1/2" of pedal travel from rest. Like a maintain cruising speed amount. 

 

It will only upshift under 3300RPM or so at TPS level 3 or under. It will downshift at level 5 or over. Explains why it's soo touchy. 

 

My TPS 5v and ground are fine, I'm reading about 0.56V closed throttle. FSM just says it should be greater than 0.2V and less than 1V. 

 

I don't know why it ramps the throttle numbers so fast. TCU shares TPS signal voltage and ground with ECM. 

 

Any ideas? Mopar TPS are discontinued

[cruiser54]

Maybe this will help:

 

CRUISER'S MOSTLY RENIX TIPS

RENIX TPS ADJUSTMENT

OCTOBER 30, 2015 SALAD 198 COMMENTS EDIT

 

Before attempting to adjust your TPS, there are a few things that need to be done.

1.  Be sure the throttle body has been recently cleaned. It’s especially important that the edges of the throttle butterfly are free of any carbon build-up.
2.  With the KEY OFF, and using the positive (red) lead of your ohmmeter, set on the lowest scale, probe the B terminal of the flat 3 wire connector of the TPS. The letters are embossed on the connector itself.
3. Touch the black lead of your meter to the negative battery post. Wiggle the wiring harness where it parallels the valve cover and also over near the MAP sensor on the firewall.

If you see more than 1 ohm of resistance, or fluctuation in your ohms reading, some modifications to the sensor ground harness will be necessary. The harness repair must be performed before proceeding. It is covered in detail in Tip 6.

TPS ADJUSTMENT FOR ENGINE ISSUES

Both Renix manual and automatic transmission equipped XJs and MJs have a flat three-wire connector to the TPS which provides data input to the ECU. The three wires in the connector are clearly embossed with the letters A, B, and C. Wire “A” is positive. Wire “B” is ground. DO NOT UNPLUG THE CONNECTORS!

1. KEY ON, measure voltage from “A” positive to “B” ground by back-probing the connectors. Note the voltage reading–this is your REFERENCE voltage.
2. KEY ON, back-probe the connector at wires “B” and “C”. Measure the voltage. This is your OUTPUT voltage.
3. Your OUTPUT voltage needs to be seventeen percent of your REFERENCE voltage. For example: 4.82 volts X .17=.82 volts.
4. Loosen both T-20 Torx screws attaching the TPS to the throttle body and rotate the TPS until you have achieved your desired output voltage.
5. Tighten the screws carefully while watching to see that your output voltage remains where it is supposed to be. If you can’t achieve the correct output voltage, replace the TPS and start over.

Sometimes, after adjusting your TPS the way outlined above, you may experience a high idle upon starting. If that happens, shut the engine off and reconnect your probes to B and C. Start the engine and while watching your meter, turn the TPS clockwise until the idle drops to normal and then rotate it back counterclockwise to your desired output voltage.

TPS ADJUSTMENT FOR AUTOMATIC TRANSMISSION ISSUES

Renix automatic transmission-equipped XJs and MJs have a TPS with two connectors. There is a flat three-wire connector, same as the manual transmission vehicles have, and it is tested the same as outlined above—FOR ALL ENGINE MANAGEMENT RELATED ISSUES.

However, the automatic TPS also has a square four-wire connector, clearly embossed with the letters A,B,C, and D. It only uses three wires and provides information to the Transmission Control Module. THIS SQUARE FOUR WIRE CONNECTOR IS USED FOR TRANSMISSION/SHIFTING RELATED ISSUES ONLY.

First off, DO NOT UNPLUG THE CONNECTORS!

1. KEY ON, measure voltage between “A” positive and “D” ground by back-probing the connector. Note the voltage. This is your REFERENCE voltage.
2. Back-probe the connector at wires “B” and “D”. Measure the voltage. This is your OUTPUT voltage.
3. Your OUTPUT voltage needs to be eighty-three percent of your REFERENCE voltage. For example 4.8 volts X .83=3.98 volts.
4. Adjust the TPS until you have achieved this percentage. If you can’t, replace the TPS and start over.

So, if you have an automatic equipped XJ your TPS has two sides–one side feeds the ECU, and the other side feeds the TCU.

For those with a MANUAL TRANSMISSION–the TPS for the manual transmission XJs is stupid expensive. You can substitute the automatic transmission TPS which is reasonably priced. The square 4 wire connector is just not used.

[Strokermjcomanche]

1 hour ago, scguy said:

Hooked up the $12k Snappy scanner today to watch the trans data. It's about what I was thinking, when it was delaying shifts, the solenoids are not being commanded. The speed sensor is reading fine, my issue must with the TPS. 

 

The scanner reports TPS in 8 steps, 0-7. Closed throttle reads 0, but it ramps very fast to 4 and 5, I'm talking about maybe 15-20% throttle. It goes through 1-4 in less than 1/2" of pedal travel from rest. Like a maintain cruising speed amount. 

 

It will only upshift under 3300RPM or so at TPS level 3 or under. It will downshift at level 5 or over. Explains why it's soo touchy. 

 

My TPS 5v and ground are fine, I'm reading about 0.56V closed throttle. FSM just says it should be greater than 0.2V and less than 1V. 

 

I don't know why it ramps the throttle numbers so fast. TCU shares TPS signal voltage and ground with ECM. 

 

Any ideas? Mopar TPS are discontinued

There are a couple mopar TPS on eBay , I believe the numbers are 33004650 

[scguy]

Well, I decided to try a new throttle position sensor to fix the shifting issues and it did! I used a Car quest TPS, instead of OE just because I could return it if it didn't fix it, but it ended up fixing the problem. The old TPS was in spec for idle voltage and WOT voltage, but it scaled too quickly somehow? In my 16 years of professional auto repair, I've never seen that before. 

 

It upshifts and downshifts just fine now. 

[Strokermjcomanche]

Good to hear