TPS error P0123 help

[dgt]

Hi all,
I have a 1999 TJ 2.5l 5 speed manual. I get a P0123 error. I replaced the TPS AND
The PCM. Checked the operating voltage of the TPS and its OK. Wiring is good.
I still get the error immediately after clearing it at idle. Engine runs ok mostly
Through the driving RPM range but has a flat spot which runs rough. The only
part I haven't replaced Is the battery temp sensor which is in line with the ground of the TPS which
I will replace tomorrow. Does anybody have any experience with this problem,
The replaced TPS is a Mopar part, the PCM is an online remanufactured unit.
This is my first post. Thanks for any help in advance.
Dave

 

[SteelHeadz]

So is the P0123 is still setting of the SES lamp?

 

[dgt]

After replacing the BTS, there is no change. Everything is as before.
I am stumped. Next option is to obtain a complete wiring diagram
For that area and chase the problem down. All I have is a Haynes
Manual for it that I don't think is complete.

 

[SteelHeadz]

Try this, Remove the upper and lower steering column cover and locate the connector for the clockspring under the column, behind the steering wheel. Disconnect the clockspring and recheck it for the P0123 DTC. If the dtc does not come back after disconnecting the clockspring, replace the clockspring. The thoery is that the 5V supply to the clockspring is shorted to ground and is causing the PCM to have an erroneous dtc of P0123. If this doesn't apply after you've done this test, post back and i'll walk you thru another test..

 

[dgt]

SteelHeadz,
Thanks very much for your post! I proceeded as you advised and the CEL did not come back on. I called my parts house to try and get a replacement. They don't sell them. I then called the dealer. They want $209.00 for one, however I cannot have one as he shows 400 of them on backlog throughout the US and none in transit. I will have to hurry up and wait to get hosed.
I asked if it was safe to drive the vehicle with the clockspring disconnected ( I dont want the airbag deploying suddenly), they siad yes it was. They also said I could disconnect the horn relay. I reconnected the clockspring and disconnected the horn relay. Again no CEL light.
I can now get my Jeep smogged as there is no CEL light preventing me from doing so.You were right on with the information and I thank you very much.
Dave

 

[southtj]

Mikey is the man!

 

[SteelHeadz]

Thank's Todd. That was a shot in the dark. Looking at the schematic diagram ,it made sense and i'm thankful that Dgt didn't ask what the heck that had to do with the TPS cause i would have had a heck of a time explaining that one.:lol:.

 

[phall92139]

There is a vendor on E-Bay that's offering...
"Good used Jeep Wrangler TJ Airbag clock spring. This is for a TJ without cruise control. Has been tested and is in working order and centered properly. Will fit TJ model years 1997-2002 without cruise control."

Price: $99.95 + $9.95 shipping.
http://cgi.ebay.com/ebaymotors/Jeep...emQQimsxZ20090621?IMSfp=TL0906211410003r32833


The vendor has been an E-Bay member since '99 and has a 96.9% positive feedback rating so maybe it's worth a shot.

 

[dgt]

Mikey is the man!
Agreed!

The semi-final test (before I replace the clockspring) was a test drive. That went very well. My Jeep runs great. I suppose the new plug wires, Dist. cap, etc from my initial shot at repairing the stumble helps. No stumbling at cruise RPM, no CEL, just good Jeep driving. I do not have a horn though. I guess I'll just have to stick to the back roads Heh, Heh.
I was able to return the BTS, no problem. My next task is to try and return the PCM to Auto Computer Exchange. They were very easy to work with when getting an extension to return the core. I have a feeling they will allow the return but I imagine I will get hit with a re-stocking charge. That's fair though. I haven't read the paperwork yet.
As for how the clockspring affects the TPS, relax Mikey I won't ask. I can't tell from the schematic, but when I replace it I will most likely be able to figure it out. Being an electronics geek for a living I am driven to discover the unknown in the electronics world. I will most likely also at least attempt a repair for the old clockspring. I would be surprised if I cannot make it work again.
If any one is interested in the return of the PCM and repairing the clockspring, I would be happy to post the results.
Thanks again,
Dave

 

[dgt]

Also, thanks Phil I will check out the offer on ebay.

 

[SteelHeadz]

For the Horn, get a bumper sticker that say's " No horn, Watch for the finger". LOL. As for repairing the clockspring, been there done that, that's part of what i do. The clockspring is a modular unit that has a wound up ribbon wire inside the housing. It usually breaks on one end or the other. They are not a servicable part. Repairs are avoided due to liabilities. Although a clockspring has not been known to deploy an airbag prematurely , i wouldn't risk being the one to be the first one for that reason.

 

[dgt]

SteelHeadz

"They are not a servicable part. Repairs are avoided due to liabilities."

I understand completely, but I have to try, because

"that's part of what i do"

If I wasn't confident in my repair I wouldn't think of reusing the defective part. I will also try to waterproof the replacement before installation. By the way, will the airbag still deploy in the event of a collision if the horn relay is removed? Again, I cannot tell from the schematic.

 

[SteelHeadz]

Yes it will. so as long as the connectors are in place on the clockspring and the airbag lamp is off, the airbag is operational. The connector is yellow in color throughout the vehicle harness.