I say forget the clockspring for now. If you do want to check the clockspring just make 100% sure the airbag capacitor is fully discharged by disconnecting the battery negative cable and leaving the Jeep sit for a minimum of five whole minutes prior to messing around anywhere near the steering column! It is very dangerous if you do not! You have to make sure you have the steering wheel centered and do not move the wheel around any when disconnecting the clockspring until you re-plug the clockspring back together again too. I do not think it is the clockspring. It is still a possibility to keep in mind though.

I think your next step should be to unplug the TCM. The TCM could cause the problem to occur exactly how it is happening on your Jeep. The ECU, TCM, and the TPS are inexplicably linked together with one another. After thinking about it, if there is a short in or at the TCM you could expect to see the results like how you are seeing with 5V on the TPS signal wire. If you follow and trace the TPS signal wire I bet you will see the TPS signal wire splits into two somewhere in the engine compartment if you were to look within the harness... It splits with one portion going to the PCM and the other going to the TCM. It makes very good sense to me now, this could very likely be the reason for why you are seeing the problem happening like this at the TPS.

Unplug the TCM and see what happens. If the problem goes away then replace the TCM from a junkyard Jeep if you can, as they are inexpensive to replace this way. Prior to replacing the TCM, inspect the entirety of the TPS signal wire from where it branches off going to the TCM and inspect any areas where you did the recent work.

Too much of a coincidence, you know. The TCM and TPS have too close of a relationship with the signal wire to look over this anymore in my mind.. with having those test results you obtained.

 

Update,

I decided to change out the complete throttle body with the 3 sensors from a wrecked 2001 Cherokee.

It seems to have fixed the problem. At least sitting in the shop. The codes haven't come back on yet. (they would come back on immediately before)
And the 5 volts on the signal wire are gone.

I have to do a couple things before I can test drive it. I will follow up after I do that.

This is the stuff that drives me crazy with electrical work.

thanks for everyone help and advise.

Joe Walters

 

👽

 

Noah911

The wiring diagram I have shows the signal wire going from the tps to the tcm then to the pcm. So what you say makes sense if I have to go further.

The reason I decided to change the throttle body and sensors was because when I tested the resistance between the tps signal and ground on both of the tps sensors I found the resistance was quite different between the two. Even though the sweep test was smooth thru the range . Very strange to me. But I don’t do much of this kind of thing.
And I couldn’t just swap the tps easily because the screws were stripped on the one.

What I don’t understand is why I was getting high voltage at the tps plug when it was disconnected. Possibly feedback from something else I quess.

I still haven’t driven it. But I’m pretty sure it’s fixed. No codes came up right away. And looking at live data, the tps was now reading about 17% at idle where it was reading 98% before I changed it. Plus it didn’t stall like before. So I’m hoping it’s good to go.

You mentioned resetting the pcm. If my test drive is good tomorrow, should I look into doing that?

thanks again for your help.

Joe W

 

My curiosity would probably get the better of me. I think I would have to put the other TPS back on the throttle body again, and see if the results of getting 5 VOLTS on that other sensor has repeatability as compared to the newer replacement TPS to be normal.

Do not forget to reset the PCM.

 

awg responded earlier and said what you just quoted about the 5 volts on the signal wire meaning a probable bad tps.

Im glad we both learned something here today

 

Nah... I do not think that is it. It believe it is a normal finding.

If I understand how this sensor works in coordinating things with the PCM to make the signals it does., I bet if you were to unplug this newer sensor you have on there right now.. I bet you would probably get the same result of having 5 VOLTS on that harness side signal wire too. I could be wrong about this? Which was why I decided not to answer that part of your questioning. Plus, if I am right about it? Then, you would of had to of just taken my word for it. As I am not sure how I would have went about trying to explain it to make sense...

 

I will probably do more testing later.

First I have to get the stripped screws out of the original throttle body.

I will research resetting the pcm. That’s new to me.

I ordered a new Mopar tps so I can put the other engine back together. Plus I didn’t want to send my son out with a old unknown sensor.

 

I did check the voltage again. With the sensor unplugged i think it read .22. I didn’t write it down. But I know the 5 v was gone.

if I have time tomorrow, I’ll double check it.

 

amg,

It looks like you win the cigar.

it didn’t make sense to me because I was getting the high reading with it unplugged. I thought that would eliminate the tps.
learn something new everyday.

thanks

 

If that is true? Then, there is definitely conflicting information out there about it. Which is not suprising. I try to reserve judgment when reading stuff like this from unofficial sources. It made sense with what they were saying for how and why it is like that. Although, other unofficial sources I went to regarding this here stated the opposite... I did not really know what to believe about it in the end, so just let it be a mystery.

 

If the TPS was unplugged, but you still had 5v on the sender wire, then logically (imo) that actually is indicative the TPS would likely NOT be the offender.

I would be very suspicious of the TPS wires, jiggling them may have separated the touching short.

At any rate, well done for getting it going, you have some spares now, and clues if it plays up again

even though you say you are not an electrical guy, its essential to free download the FSM from Cruiser54 website..has the circuit diagrams, specs and fault finding info

 

awg,

yes, the high voltage with it unplugged is what had/has me confused too. It was 4.68 v unplugged. It went a little over 5 volts when plugged in and back probing the connector.

I did wiggle the wires when I was testing things. The meter never flinched. Visual inspection doesn’t show anything. But I didn’t open the harness.

I will drive it tomorrow and we’ll know more. But the signs are good so far.

thanks for the tip on the wiring.

one other thing to think about is that I replaced all 3 sensors along with the throttle body.
But there were no codes for either the iac or the map.

 

"Probe the signal and ground portions of the sensor with a multimeter set to read resistance"

You also need to look at the resistance from the signal wire to the the +5v side. I'll bet that was pretty low and not changing, indicating that the signal wire was shorted to the +5-volt.

 

hi,

good idea. I didn’t do that.

thanks