97 XJ TPS circuit; HELPPP!

[volaredon]

this is on my wife's XJ; been down over a month;
It started running erratically; trans not shifting right; high idle; surging;
I have had a few codes pop up, mostly PO0123 high TPS; but have had TPS does not agree w/MAP, at times.
I am showing a MAP voltage of 4,69 WITH TPS DISCONNECTED it goes down to 4.41 when I plug it in; being it shows this voltage disco'd I can pretty much rule out teh sensor; though I have swapped on a "known good" one with same results; I have swapped out the ECM (twice) and went checking out the harness, it was all a melted glob like pulling Twizzlers apart; (making for bare wires) so I went junking again and got a complete engine harness from another 97 XJ (Finding specifically a 97 model in the boneyards, was worse than a needle in a haystack, surrounding years was easy)
I found several entries online about the airbag clockspring possibly causing this; I have it disconnected at the moment; no change;
I know taht having the #1 plug disconnected from the ECM should make the voltage at the TPS sensor go dead; it does NOT do so; still have voltage there. I am at my wits end trying to chase this short down; any other ideas? I have cleaned EVERY ground connection I have come across to a point of being shiny metal, and added additional grounds that were never there originally from firewall to block as well;

The PO had an Avatal remote start installed; which had a mind of its own and would randomly start at will without touching the remote (in my wife's work parking lot, or at weird times while everyone is dead asleep) nor ever being programmed to start once an hour when cold (Ive been told it had this but I didn't even know how to activate it) yet its "start when it felt like starting" usually happened in warmer temps;
so I removed the remote start and put it out of its misery with the assistance of a 3 lb sledge, then resoldered and retaped EVERY wire under the dash that was tapped into, in order to wire this piece of crap in;

one other thing; 3 days before this I steam cleaned the engine compartment; it ran fine that evening afterward, also everything was fine the next day; problems started the day after that. (I wish I'd have jacked it up and done the whole underside as well, I have an 18 YO that sems to think he has to hit every puddle/mudhole he sees)
New ECM, new harness and a month in between its last use to dry anything out should be sufficient; ONCE I also got a PO0700 related to the transmission but was referred back to the PO0123 TPS code to repair first;
I reset the ECM with the Snapon Brick and the code resets within seconds, key on engine off.

 

[volaredon]

I'm drowning and gettin tired of A) my wife complaining about having to drive a vehicle with a Clutch pedal; (ie, my 97 TJ) while I try to figure out her XJ headache
and B) not being able to drive the TJ, because she has it!!!!

and also why I still have 2 CARBUETED vehicles hanging around!
My 83 Dodge 3/4 ton's 318 has never failed me;
sadly my 78 Fury sits due to having to carry an 18 yo boy on my insurance..... may have to put it back on and take the XJ off til I can figure it out; my son and I both start college in a week 50 miles apart from each other so I NEED this XJ back running!!!
Once that happens I can rebuild the 727 in the kid's Ramcharger..... it's almost dead too, we are nursing that one along til the XJ runs again.... I cannot have 2 vehicles down!

PLEASE , guys, HELP!!! has nobody had such a problem?

 

[BigBird04]

Wish I could help but I've never had nor heard of anyone I know having that problem. If it were mine I would probably start checking/changing every sensor, then looking at the fuseable links(grab them and try to pull on them to see if they stretch like a rubberband). Wish I could be of more help but good luck I hope you can get it figured out, nothing sucks like a problem you can't figure out.

 

[volaredon]

I don't see any fusable links (I know what they are have been bitten by them before) I believe that they went away from them when they went to the dual fusebox one in the cabin and one under the hood; I have a replacement wire harness on there. I have been checking everything (that I could think of) but have gotten wind of a couple more earlier today but came home with my knees "on fire" (3 solid days of clearing riverbank, and dragging limbs uphill by HAND might have something to do with that, so NOT worth the min wage that seems to be all the jobs available these days) so I couldn't get to it; project for tomorrow if the rain they are calling for holds off.
I have the factory service manual for this Jeep and boy did they complicate the manuals from a few years prior; I hunted and hunted thru there and saw no mention in the wiring schematic of any fuseable links..... but thanks for the thought....

 

[volaredon]

Screaming UNCLE for now; the insurance is off the Cherokee, it is parked in the garage (mine; I could not afford to spend $80+/hour if I wanted to, on disability) until I can get my head to stop spinning long enough to become un-confused so i can hit it again witha clear mind and start over; meanwhile I pulled my old car out of the barn and my wife can drive it at least til snow is forecast;
it's my only "car", a 78 Plymouth Sport Fury 2 door hardtop. 49K original miles.

 

[altan]

Ok so in short what is wrong with the jeep what is it doing and what code

 

[volaredon]

A REPLY!! thanks... lots of crickets lately.... I'm out of popcorn and I'm not a coffee drinker (Coke Pepsi or RC and no diet version, either!!)
All kidding aside I thought I put that in my initial post; the symptoms; some test results, and such; it's after 11 PM 6AM will be here way too quickly, I'll review my OP tomorrow and if I didn't put that info in there (like I thought I did) I'll add to it; right now I'm too bleary eyed.... (just tired; no added substance involved)

 

[altan]

The sympton you explain leads mr to belive its the tp Did you change the tp sensor because the transmissions shift points is controlled by the out put of that sensor

 

[volaredon]

no I have not replaced the TPS; I am getting a 4.59V signal via the scanner and 87% throttle application with nobody in the vehicle (nothing touching the gas pedal) key on engine off and the TPS DISCONNECTED! so having that kind of voltage showing for a sensor that isnt even connected tells me the sensor is not the problem! I did pop one on there that I have laying around (known good but used) and no change)
Also; of the 3 wires that go to the TPS (solid orange, orange/blue stripe and tan/yellow) the orange is supposed to be a 5 volt reference taht also goes thru 4 other sensors; with the COMPUTER PLUG UNHOOKED and everything else also unplugged that the orange wire goes thru if I hook up either the crank sensor or the MAP I get 7V on taht orange; it is supposed to be dead because I still have it disconnected from the computer!!!
I have replaced the wiring harness since the original was a melted glob where it passes actross the intake and peeled apart/insulation tore while I was looking for a factory splice that is in that area for ground side; also I have replaced the computer. and NO CHANGE. Something somewhere is bleeding voltage thru to that orange 5V that is not supposed to be. I have checked for continuity and for a short across the 3 circuits that go to that plug at the TPS to see where the 7V could be bleeding thru from til the cows came home and am now starting to yank out my hair over this thing.

 

[altan]

Well I am going to look thru the wiring diagrams for that jeep at me work what is the production date of that jeep is it in 96 or 97 because the 97 xj built from 6 month of 96 to the 12 are different then 1 st month of 97 till the 5 th month

 

[volaredon]

I am not looking at it right now but IIRC it is Feb of 97; when I went to the stealership to ask about a wire harness they said it had to come form a '97 only; there was no "has to be from before______ (date) or after________". as long as it has a 4.0 A/T, 231 T case and from a 97 it's the right harness"; there were like 8 P/Ns listed but some were for XJs with a 2.5, or with a stick, and one for an XJ with a 242, etc,
I did not replace the whole harness just the "engine" part, where it has connectors at the back of the valve cover. ( didnt cut /splice the harness in, just unhooked it at that point;
I cleaned/shined up all the grounds and the mounting fasteners while I was at it and even added an additional ground from the firewall to the engine.
I have been thru this thing with the scanner (Snapon 2500) and a Fluke multimeter along with the factory service manual;
As compared to older vehicles that I have worked on with the "help" of the Chrysler factory service manual (and even the same-year Ram 1500 that I used to have) the Cherokee one is only good for one thing; sending me on wild goose chases, references to other sections that are likewise no assistance and confusion.

 

[volaredon]

crickets.... popcorn... my pot of coffee is empty and this Jeep SITS.

 

[altan]

Well I got a copy of the wireing diagram now I got to get a pot of coffee and trace the wires

 

[volaredon]

any insight will be appreciated; I have the Chrysler factory service manual for it but as compared to other factory service manuals this one makes my head spin;
I'm back in school now (18 credits worth, 5 classes, 3 of which with "labs" attached so it's like having 8 classes) and just swapped due to the return of school from the 7-3 shift to 3-11. I have from the time I get up til about 2:40 each weekend day coming up that I can play with the thing and try (re-try in some cases) some electrical tests with the scanner and the Fluke..... I really do need to get to the bottom of this. I moved it into the garage a week ago and shut the door, the previous month though with "just" working I confused myself and got my brain in knots; so it needed to go out of sight for a while.
Time to start over from Square One and this time write down test results as I have forgotten alot of them I did and confused the results of others.....

 

[altan]

Everything I am reading leads me to get you to try this flow chart Hope it helps and if you need another one let me know

TEST TC-27A - THROTTLE POSITION SENSOR VOLTAGE HIGH

NOTE: For connector terminal ID, see CONNECTOR IDENTIFICATION DIRECTORY. For component location see wiring diagram in the WIRING DIAGRAMS article.

Turn ignition on. Using scan tool, read Throttle Position (TP) sensor voltage. If voltage is more than 4.5 volts, go to step 7). If voltage is 4.5 volts or less, go to next step.
While monitoring TP sensor voltage, slowly open and close throttle. If voltage does not change smoothly, replace TP sensor and perform TEST VER-2A. If voltage changes smoothly, go to next step.
With throttle at closed position, wiggle wiring harness and connector going to TP sensor on throttle body while monitoring voltage. If voltage changes while wiggling wiring harness, repair wiring harness and connector as necessary and perform TEST VER-2A. If voltage does not change while wiggling wiring harness, go to next step.
Start engine. Wiggle wiring harness and connector going to TP sensor on throttle body while monitoring engine speed (RPM). If RPM changes while wiggling wiring harness, repair wiring harness and connector as necessary and perform TEST VER-2A. If RPM does not change while wiggling wiring harness, go to next step.
Condition required to set DTC is not present at this time. THROTTLE POSITION SENSOR VOLTAGE HIGH DTC sets in Powertrain Control Module (PCM) if TP sensor voltage at PCM is more than 4.5 volts for .704 second. Possible causes are: open TP sensor wiring or defective TP sensor. Go to next step.
Check for defective wiring and connections at TP sensor and PCM. Repair wiring and connectors as necessary and perform TEST VER-2A. If wiring and connectors are okay, see INACTIVE DTC CONDITION. Test is complete. Perform TEST VER-2A.
Disconnect TP sensor connector. Inspect connector and terminals for damage. Repair connector and terminals as necessary and perform TEST VER-2A. If connector and terminals are okay, go to next step.
Using an external voltmeter, check voltage on TP sensor connector, signal circuit (Orange/Dark Blue wire). If voltage is more than 5.5 volts, repair short to voltage in signal circuit and perform TEST VER-2A. If voltage is 5.5 volts or less, go to next step.
Connect a jumper wire between TP sensor connector, signal circuit (Orange/Dark Blue wire) and ground circuit (Black/Light Blue wire). Go to next step.
Using scan tool, read TP sensor voltage. If voltage is less than one volt, replace TP sensor and perform TEST VER-2A. If voltage is one volt or more, go to next step.
Remove jumper wire and reconnect jumper wire between ground and TP sensor connector, signal circuit (Orange/Dark Blue wire). Go to next step.
Using scan tool, read TP sensor voltage. If voltage is less than one volt, repair open ground circuit and perform TEST VER-2A. If voltage is one volt or more, go to next step.
Turn ignition off. Disconnect Powertrain Control Module (PCM) connectors. Inspect connectors and terminals for damage. Repair connectors and terminals as necessary and perform TEST VER-2A. If connectors and terminals are okay, go to next step.
Using an external ohmmeter, check resistance of signal circuit (Orange/Dark Blue wire) between TP sensor connector and PCM Black connector. If resistance is less than 5 ohms, replace PCM and perform TEST VER-2A. If resistance is 5 ohms or more, repair open signal circuit and perform TEST VER-2A.

 

[altan]

Pm me your email it looked better and had numbers in my email lol

 

[volaredon]

Pm me your email it looked better and had numbers in my email lol

OK will do;

As far as the TPS; I have 4.69 V thru the scanner on the TPS WITH THE TPS DISCONNECTED!!! under that condition I should have 0.
When I connect the TPS I have 4.92V key on eng off nobody touching the throttle (I have the cable unhooked from the throttle body)
so having this voltage with the sensor disconnected tells me the sensor IS NOT the problem.

With the computer disconnected, I have nearly 7V on the solid orange 5V reference signal; again with the computer unhooked, that number should be 0.

I went thru the wiring diagram and found everything tthat solid orange feeds; O2, Hall effect crank sensor MAP and TPS; with all unhooked (computer plug as well) I have no juice on that orange as I would expect; to plug in EITHER the MAP or crank sensor (and nothing else in that list) my 4.69 comes back and my 6.69V on the orange comes back;
So being the crank sensor being the 1st thing in line off that splice I went and bought a new crank sensor and didn't install it but just put an alligator clip to the mount bracket and plugged it into the wiring harness; no change vs with the original crank sensor; so I returned the new one.

I then noticed that I have 5.XX V on the brown/yellow wire which is where the TPS is supposed to get ITS GROUND! again this is with the comoputer DISCONNECTED!
I ohmed between all 3 terminals at the TPS, 2 at a tine to see if I showed continuity between any; none noted;
I have seen numerous threads regarding the clockspring possibly being shorted via the cruise control (which does have a tie to the TPS) so I have the clockspring unhooked; no change.
I have unhooked the brake light switch on the brake pedal arm and again no change.

I have replaced the computer and the wiring harness and NO CHANGE.
(it does run different with the other computer, as in it idles at 800-ish rather than 1250-ish as with the original computer)
the orig harness tore apart as I was looking for various splices as shown in teh service manual; the whole orig harness was a melted together glob that reminds me of pulling apart Twizzlers candy; as I did the insulation tore and 2 wires shredded and came apart
I checked with my dealer parts buddy who told me this harness etc is "1997-only" and I went to every junkyard between here and Hammond Indiana (60 miles and several junkyards to choose in between here and there) before I specifically found a 1997 Cherokee; it was even a "Country" model just like mine
Plenty of 96s 98s and 2000's and tons of GRAND Cherokees but I cannot believe it took me that long to find a 97 in the yard!

(there is one in a yard 3 miles away and it was the 1st place I went but it looked like the Hatchet Man got to it and its harness before I did; snipped/cut in like 6 places...... the rest of the underhood wiring harness appears intact, that the engine harness plugs into; I think that will be my next step to go get the "rest of" the underhood wiring harness and maybe the dash harness from this wrecked 97 Cherokee)

 

[volaredon]

Had a phone company tech-buddy come by with a "tone machine" they use for finding shorts in the 2000-wire bundles in those roadside "towers" he thinks I somehow have a short with the fuel pump circuit and that being where my back-feed is coming from; I need to search that PITA schematic to see if there's any place that the wiring for both comes close to each other;

 

[volaredon]

well this thing has collected way too much dust and winter in Chicago is coming too fast; I finally found a complete eng comp wiring harness that hasnt been cut apart and such; AND that will supposedly work (I got one from a 98; dealer says 97-only yards say 97-98 are the same) I could NOT find a 97 in a yard to save my life; as it was the 98 I pirated the harness from was over 2 hours away from here....I hope beyond all hope that this will get my XJ rolling again.

 

[volaredon]

I have spent several afternoons and several tanks of gas searching for a suitable wire harness donor; I got a harness off a 98 and no good; some things are different. Found out after (not the 1st) 4 hour roundtrip to a yard and pulling it then spending ALL DAY (so far) swapping the harness onto the garage ornament.

if what they say is true that 97 was the highest XJ prouction then why doesnt that reflect in junkyard population? I see tons of '92s 94s 95s and 6,s as well as 98s/99s but NO 97s in any junkyard within a 2 hour drive radius of me....