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Trans won't up shift.

I'll disconnect mine and go for a spin later and let you know. It should probably still shift, since it would still see speed, but firmness and shift timing would likely be compromised.
 
btam13 said:
When you unplug the TCU pigtail of the TPS, should the trans be able to be shifted through the gears manually? If so, at what RPM would the trans shift at? I tried this on mine but only took the RPMs up to 3000 and then tried to shift it manually. No shift happened. Thought this might isolate the problem to the TPS for confirmation.
Click to expand...

If you disconnect the TCU, it will shift manually using the shifter. IN 1-2 it needs to get up over 4,000 or 4,500 rpm to shift to 2nd, but it will shift in 3rd earlier if you shift from 1-2 to 3 manually.

I it does not shift manually as you go from 1-2 to 3 and then to 4, with the TCU disconnected, you have AW4 problems internally.
 
I think that the TPS is shot. Last night I used a volt meter to test the input voltage to the TPS on the TCU pigtail and got about 4.8 volts. I then checked the output voltage and got nothing. Zero! Had to put the TPS back the jeep since I already took it off thinking I could bench test it. Now, I'm not completely confident that I tested it right but I believe I did. Have to pick up the new TPS after work. Is it better to test input and output voltage using the battery negative post as the ground?
 
Ecomike said:
If you disconnect the TCU, it will shift manually using the shifter. IN 1-2 it needs to get up over 4,000 or 4,500 rpm to shift to 2nd, but it will shift in 3rd earlier if you shift from 1-2 to 3 manually.

I it does not shift manually as you go from 1-2 to 3 and then to 4, with the TCU disconnected, you have AW4 problems internally.
Click to expand...

I didn't let the RPMs get that high before I figured it wasn't going to shift and stopped trying I let it get to 3000 RPMs with no notice of a shift from 1st to 2nd and then tried to manually shift to 3rd with no notice of a shift. Should I try again and let the RPMs get higher just to rule out AW4 internal problems?
 
btam13 said:
I think that the TPS is shot. Last night I used a volt meter to test the input voltage to the TPS on the TCU pigtail and got about 4.8 volts. I then checked the output voltage and got nothing. Zero! Had to put the TPS back the jeep since I already took it off thinking I could bench test it. Now, I'm not completely confident that I tested it right but I believe I did. Have to pick up the new TPS after work. Is it better to test input and output voltage using the battery negative post as the ground?
Click to expand...
No, it is best to test the TPS ground wires to the battery negative post, power off, with ohm meter first. If either is more than 1 ohm, you have a bad ground. Find the bad ground connection and fix it, or run an extra ground wire from the bad TPS ground wire to the battery negative post. Once you have verified that the ground wires are less than 1 ohm to the negative battery post, then and only then do you calibrate the TPS. Then it won't matter where you conect the meter ground. Fixing a bad ground wire will change the TPS readings, and the calibration, that is why the grounds should be checked and fixed if needed first, before doing the calibration.

If it completely refuses to shift into a higher gear while in 3rd on the shifter, than I would say you have a transmission problem too, or a shift linkage problem.
 
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btam13 said:
I didn't let the RPMs get that high before I figured it wasn't going to shift and stopped trying I let it get to 3000 RPMs with no notice of a shift from 1st to 2nd and then tried to manually shift to 3rd with no notice of a shift. Should I try again and let the RPMs get higher just to rule out AW4 internal problems?
Click to expand...

With the TCU completely disconnected, shifting the shifter into third gear, should shift the AW4 into second or third gear if you are doing say at least 20 mph IMHO. lawsoncl should be able to confirm that.
 
Ecomike said:
No, it is best to test the TPS ground wires to the battery negative post, power off, with ohm meter first. If either is more than 1 ohm, you have a bad ground. Find the bad ground connection and fix it, or run an extra ground wire from the bad TPS ground wire to the battery negative post. Once you have verified that the ground wires are less than 1 ohm to the negative battery post, then and only then do you calibrate the TPS. Then it won't matter where you conect the meter ground. Fixing a bad ground wire will change the TPS readings, and the calibration, that is why the grounds should be checked and fixed if needed first, before doing the calibration.

If it completely refuses to shift into a higher gear while in 3rd on the shifter, than I would say you have a transmission problem too, or a shift linkage problem.
Click to expand...

I wouldn't imagine an internal transmission or shift linkage problem would manifest itself just from degreasing the engine. I think I am going to concentrate on the grounds and a new TPS after work and see where that takes it. Oh, and I am definately adding a ground from the TCU pigtail on the new TPS just for good measure.
 
btam13 said:
I wouldn't imagine an internal transmission or shift linkage problem would manifest itself just from degreasing the engine. I think I am going to concentrate on the grounds and a new TPS after work and see where that takes it. Oh, and I am definately adding a ground from the TCU pigtail on the new TPS just for good measure.
Click to expand...

Well I don't know if the manual shift valve is different, or entirely seperate from the solenoid activated shift valve. It they are seperate circuits, I guess it is possible for the manual shift valve to die, and the electric actuated shift valves to work once the TPS is fixed. But I don't know the entire layout of the valve body, so I am not sure. I have been told repeatly, that if it shifts manually and not automaticaly, the AW4 is OK and the TPS is bad (in general anyway).
 
Hey, just had a thought! What if any of us with a Renix 4.0 were to take the ground wires that are located on the passenger side engine block, minus the negative battery cable and extended then up to the negative battery post? Would that be a more stable ground and would it make the battery ground more stable being the only one attached to that location. Could even add a same gauge cable from that location on the block down to the frame rail. Just an idea.
 
Ecomike said:
Well I don't know if the manual shift valve is different, or entirely seperate from the solenoid activated shift valve. It they are seperate circuits, I guess it is possible for the manual shift valve to die, and the electric actuated shift valves to work once the TPS is fixed. But I don't know the entire layout of the valve body, so I am not sure. I have been told repeatly, that if it shifts manually and not automaticaly, the AW4 is OK and the TPS is bad (in general anyway).
Click to expand...

So, I should try to get it to shift manually by letting the RPMs get past 4000?
 
Ok, I installed the new TPS after cleaning the ground at the passenger side block and the one on the head on the drivers side back corner. Adjusted the TPS to .82 volts between the C and B wires on the ECU pigtail of the TPS even though I originally thought that it was suppose to be set while reading the output voltage of the TCU pigtail but took a chance on doing it the other way when I figured out that the TCU pigtail doesn't have a C pin. Took it out for a test drive. Results, trans shifts pretty good now through all gears at about 2500 to 3000 RPMs at WOT. Idle is a too low for my liking though. About 450 RPMs at Idle in park and 350 at idle in drive. Oh, and it died on me once while pulling into a parking lot but started back up fine. Rechecked the TPS adjustment. Still .82 volts. DID NOT install a ground wire from the TPS to the negative post on the battery though. I wasn't sure whether to splice it in on the ECU or TCU pigtail or both. Or whether to splice it in on the TPS side of either connector or on the harness side of the connector. I really need to learn more about using the multimeter I bought today also. I really want to be able to check the resistance in my grounds. Over all, I think I am back to where I was before the trans stopped shifting automatically. Any thoughts on the low idle or if I did anything wrong?
 
btam13 said:
Are we talking about the whole 3 key cycles thing?
Click to expand...

No, just disconnect the battery for an hour to clear the old sensor memory data in the computers, then reconnect and give it a good drive. That should fix the low idle.

The ECU and TCU sides of the TPS have diffent ground wires. If you want just run one fron the battery to the TPS, then split it into a y to both sides of the TPS's ground wires at the harness side.
 
Ecomike said:
No, just disconnect the battery for an hour to clear the old sensor memory data in the computers, then reconnect and give it a good drive. That should fix the low idle.

The ECU and TCU sides of the TPS have diffent ground wires. If you want just run one fron the battery to the TPS, then split it into a y to both sides of the TPS's ground wires at the harness side.
Click to expand...

Thanks Ecomike! I will run the grounds. Did you run one to both sides of your TPS?
 
89CherokeePioneer said:
It should be shifting out of first at redline at WOT.

Also, I did go to see how mine acted with no TCM TPS connection and it isn't starting now.

I think I pissed it off.
Click to expand...

Thanks, I fixed my shifting problem with a new TPS! Is yours starting after hooking the TPS back up? If not, try what Ecomike just suggested to me about clearing the memory.
 
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