TPS: Bad Idle, High Idle, P0123 Code? We May Have a DIY Fix

[NIVO88T]

Ok guys/gals, this just happened to srtgurls car. The car would surge, idle rough then sometimes it would be gone. it progressively got worse though!

So I had time last night after getting out of work on my 12hr shift at the shop.

Having the emanage has been a great tool especially in this case since I can see TPS voltage sweep.

Last night testing things out jean noticed that when I slammed the car door the voltage with car off swept up to .86mv then came back down to .71mv(idle/throttle off).

we start looking into the Emanage wiring, found nothing. so we decide to start the car and wiggle the tps wires and sure enough the car would idle rough. At this point the emanage Throttle screen was reading voltage as high as 4.96v and 100% throttle position.

the car revved up to about 2500rpms, then it read .94mv and about 23% on the throttle screen of the emanage. This would also cycle making the car idle/stumble by itself.

I rip out the fluke DMM and start testing wires (hector helped on testing procedure as he wires aircraft too). Figured out we have a bad wire.

I separated the wires by taking the black tape off. now with the wires seperated I was able to single out each wire. there is a solid orange wire, Orange/dark blue stripe wire and a black wire with a greyish blue thin stripe.

While the car idled i wiggled each wire seperately, come to find out that the bad wire was in fact the black/grayish blue wire! Voltage was everywhere...

I decided to take the black wire out of the tps connector and this is very simple to do if you have a precision flat head screwdriver around.

If you look at the TPS connector (white in color) you will notice it has a yellow lock type device in it. this yellow lock can be removed with the tiny screwdriver. once this yellow lock is removed, you look into the connector where the black wire lays in. there you have to use the tiny screwdriver again to raise the white plastic pin lock that holds the metal wire pin to the plastic connector. once this little metal pin lock is raised you can push the black wire out the bottom of the connector by pushing on the metal pin from the inside of the connector (don't worry the green rubber water seal supposed to come out too).

Now what I did, I took notice of the wire and why would it be causing problems. While looking at the wire i noticed it was a bit limp and kept on going to the same curved position all the time. Right there and then I knew that the wire was severed internally and the only thing keeping it together was the insulation. I carefully stripped off the insulation and sure enough the top portion with metal pin of the wire fell right onto the floor.

I soldered the pieces back together, Used some heat shrink wrapping and put the connector back together.

TPS connector got plugged back into the TPS. Turn the key to the acc position. I put a small pin that i inserted into the connector and orange/dark blue wire, from there i used the DMM's + probe to read the volatage and sure enough it was reading .713mv at idle position and 3.81v at WOT position on the connector end.

I verified this with the emanage and emanage reads .71mv and 3.80v.

Put everything back together, start the car up and vroom....no high idle, stumble while playing with wires or anything.

So instead of having a dealer tell me they can't find the issue, I cured it myself.

This was not a case of the engine moving and pulling the wire out but of the wire being bent to shape for such a long time by the factory taping. after a while the wire was getting weaker and weaker. kinda when you keep bending a wire or piece of metal to break it apart.

BTW, don't forget to disconnect the battery when performing electrical work on the car.

UPDATE by coldbur- 9/3/04


"The Part Number is 5013998AA for a tps wiring harness. It comes with a connector , 3 or 4 wires with the terminals, and heatshrink tubing. The list price is $22.10"
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Update by coldbur - 4/22/05
I had another SRT come into the shop for the high idle problem, so I had parts check for a tps connector pkg for the srt. It is now available and the part number is 5013999AA, This has the proper connector for our tps sensor.
I didn't know if you wanted to update the first page or if I should put this on the most recent page.


thanks coldbur

I had this exact problem, and decided I could fix it myself, because I don't have a reliable dealership to go to.

- I'm a pretty handy guy, and have some basic electrical knowledge, but didn't think this through as well as I thought I did. With this project, you don't have that TPS connection, you're not driving your car. Thankfully, I had another car to use to go to autozone/hardware store and get the wire and things I needed to fix it. (soldering gun, heatshrink, electrical tape, 18/20 gauge wire, etc...)

That being said, this thread is EXTREMELY useful - just not wading through the 23+ pages of it. Thank you to Nivo, Hemidakota, RUGoinup, and everyone who has contributed.
I heart SRTForums

-SyberkhanX





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Link to another TPS Repair HOW-TO: HOW-TO: TPS Repair Kit

[JCert]

Awesome...that is a perfect description of what my car does at idle. You can hear it surge, kinda like it revs maybe 50 or 100 rpm, then idles like shiz. Mine has been doing it since I bought the car but has and is still getting worse over time. I have tried every different plug, gap, and wires out there to no avail. Thanks NIVO..good find. I will take a look at mine this week and see how it turns out. I will report back.

I think anyone with a rough idle should take a look at this instead of plugs, gaps, and wires.

NIVO. How far back did you pull the tape off and how much wire did you have to stripback?

[bossmann]

I just went to the dealer and he replaced the sensor and cable for free

[NIVO88T]

Quote: Originally Posted by bossmann

I just went to the dealer and he replaced the sensor and cable for free

some of us with lots of goodies would have to pay for a $208 engine harness

[NIVO88T]

Quote: Originally Posted by JCert

Awesome...that is a perfect description of what my car does at idle. You can hear it surge, kinda like it revs maybe 50 or 100 rpm, then idles like shiz. Mine has been doing it since I bought the car but has and is still getting worse over time. I have tried every different plug, gap, and wires out there to no avail. Thanks NIVO..good find. I will take a look at mine this week and see how it turns out. I will report back.

I think anyone with a rough idle should take a look at this instead of plugs, gaps, and wires.

NIVO. How far back did you pull the tape off and how much wire did you have to stripback?

I took all the tape off the wire loom and around the sensor connectors. on that harness there are 3 connectors. TPS/IAC/IAT. I redid the tape to make it stronger and this time around i taped the loom to the connector to prevent the wires from moving around much.

I also un did the wire harness from the bottom of the throttle body.

[craigswardmtb]

I actually had a bad TPS sensor. I replaced that, and it didn't fix the problem. Then i brought it to the dealer thinking it must be the wiring harness. They said they did nothing and i picked the car up and it ran perfect. Maybe the dealer just cleared the codes and reset the PCM and it then recognized the proper signal coming from the new TPS. Or at least thats my rationale as to why it didn't fix the problem immediately after i replaced the TPS and it magically was fine after i picked it up from the dealer. 3-4000 miles later and it is still running perfect. My symptoms were different than most. My car constantly idled at 3000rpms. There was never a second after the problem appeared where it ran and idled somewhat normal. The wire wiggle test didn't affect the idle control, it stayed at 3000rpms. So it somewhat makes sense that one of the resistors in the TPS may have shorted, or melted. Some seriously hot air gets blown off of the radiator onto the TPS.

Now that i have a new throttle body i think i won't be heading to the delaer if the problem recurrs. I think i may just retape the whole wiring harness just for piece of mind, including the IAC wiring. The IAC wiring looks like that has more potential for wire breaks than the TPS wiring. I reccommend taking the zip tie off of the IAC wiring that the mfg put on it. It just bends the wiring at more of an angle making it more prone to breaking.

Thanks for letting us know how you handled the problem Nivvo.

[RELENTLESS]

I don’t have this problem, however many other do and this is a great write up that should prove to be quite useful. Great job and thanks for the 411……….

[drizze99]

Nice write-up NIVO!! This will help a lot of owners out!!

[NIVO88T]

I hope this helps those who have similar problems.

[Ray00]

Quote: Originally Posted by NIVO88T

Ok guys/gals, this just happened to srtgurls car. The car would surge, idle rough then sometimes it would be gone. it proggresively got worse though!

So I had time last night after getting out of work on my 12hr shift at the shop.

Having the emanage has been a great tool especially in this case since I can see TPS voltage sweep.

Last night testing things out jean noticed that when I slammed the car door the voltage with car off swept up to .86mv then came back down to .71mv(idle/throttle off).

we start looking into the Emanage wiring, found nothing. so we decide to start the car and wiggle the tps wires and sure enough the car would idle rough. At this point the emanage Throttle screen was reading voltage as high as 4.96v and 100% throttle position.

the car revved up to about 2500rpms, then it read .94mv and about 23% on the throttle screen of the emanage. This would also cycle making the car idle/stumble by itself.

I rip out the fluke DMM and start testing wires (hector helped on testing procedure as he wires aircraft too). Figured out we have a bad wire.

I seperated the wires by taking the black tape off. now with the wires seperated I was able to single out each wire. there is a solid orange wire, Orange/dark blue stripe wire and a black wire with a greyish blue thin stripe.

While the car idled i wiggled each wire seperately, come to find out that the bad wire was in fact the black/greyish blue wire! Voltage was everywhere...

I decided to take the black wire out of the tps connector and this is very simple to do if you have a precision flat head screwdriver around.

If you look at the TPS connector (white in color) you will notice it has a yellow lock type device in it. this yellow lock can be removed with the tiny screwdriver. once this yellow lock is removed, you look into the connector where the black wire lays in. there you have to use the tiny screwdriver again to raise the white plastic pin lock that holds the metal wire pin to the plastic connector. once this little metal pin lock is raised you can push the black wire out the bottom of the connector by pushing on the metal pin from the inside of the connector (dont worry the green rubber water seal supposed to come out too).

Now what I did, I took notice of the wire and why would it be causing problems. While looking at the wire i noticed it was a bit limp and kept on going to the same curved position all the time. Right there and then I knew that the wire was severed internally and the only thing keeping it together was the insulation. I carefully stripped off the insulation and sure enough the top portion with metal pin of the wire fell right onto the floor.

I soldered the pieces back together, Used some heat shrink wrapping and put the connector back together.

TPS connector got plugged back into the TPS. Turn the key to the acc position. I put a small pin that i inserted into the connector and orange/dark blue wire, from there i used the DMM's + probe to read the volatage and sure enough it was reading .713mv at idle position and 3.81v at WOT position on the connector end.

I verified this with the emanage and emanage reads .71mv and 3.80v.

Put everything back together, start the car up and vroom....no high idle, stumble while playing with wires or anything.

So instead of having a dealer tell me they can't find the issue, I cured it myself.

This was not a case of the engine moving and pulling the wire out but of the wire being bent to shape for such a long time by the factory taping. after a while the wire was getting weaker and weaker. kinda when you keep bending a wire or piece of metal to break it apart.

BTW, don't forget to diconnect the battery when performing electrical work on the car.

The End.

thats exactly how i tested the tps voltage, with my emanage. got a new one and all the hell ended

[myfootsmells]

is there a picture of where the TPS is located? I hvae a rough idea but a picture would be best

I'm actually having some problems with my car similiar to this, I think.

i'm having a rough idle, but my needle isn't moving spordaically. on the boost gauge the needle hovers around 11 nu/in2. and i have some pretty bad smelling gas fumes.

ive replaced the entire fuel rail, i've checked the injectors, replaced the coilpack, any suggestions?

[Exhaust Depot]

Now I dont have to hear SRTGURLS mouth anymore when she calls me with issues with her emanage.

Taulked (accent) to them two yahoos lastnight and sure enough I told him what the problem was before they told me. Eo1 made it easy to troubleshoot it being that it gives you tps voltage realtime.

You dont want srtgurl on your bad side. "$)$%&($ emanage this, puerto ricans that, blah blah blah."

Now go tune the car in and dyno it and get back to us.


Yo!

[NIVO88T]

LOL..@ E.D.

yeah the yelling stopped....I don't have finger prints on my face any longer!

[reefSRT4]

Awesome write up NIVO!! My car goes to the dealer tomorrow....same exact prob. After two weeks the car finally threw p0123. The tech called me and explained STAR recommended removing the wires from the connector for inspection AND replacing the TPS. If I still have the issue after getting the car back....this is the thread I will be using as a "how-to"!!

[kotu100]

hey nivo do you think i should check mine or do you think it just idles a lil rough from the 750's?