PT Cruiser Forum  
Advertisements
       

Go Back   PT Cruiser Forum > General Forums > Tech & Performance Forum

PT Cruiser Forum

Advertisements
P0123 Throttle Body Sensor Code

 
Like Tree3Likes
  • 2 Post By chuzz
  • 1 Post By RickinPA

Reply
 
LinkBack Thread Tools Display Modes
  #1 (permalink)  
Old 15 Dec 2018, 04:47 pm
Fresh Cruiser
 
Join Date: Nov 2015
Posts: 8
Default P0123 Throttle Body Sensor Code

Check engine light just popped on yesterday on my 2007 Touring Edition (85K). Had the codes read at Auto Zone with the following results:

P0123: Throttle/Pedal Position Sensor A Circuit High Input
P0700: Transmission Control System (MIL Request)
P0733: Gear 3 Incorrect Ratio

The diagnostic recommendation is that the most likely solution is to "Replace the Throttle Position Sensor."

As I'm learning about this procedure, I'm finding out there could be other variables involved, such as bad wiring or carbon buildup inside the throttle body itself.

I have noticed a few instances recently when there was was a momentary hesitation in fuel delivery while accelerating, so I believe there is a good likelihood that it is the sensor that is bad. I wanted to ask the forum for any advice or suggestions before I try and replace the sensor myself or opt to take it to a mechanic. Thanks in advance for any suggestions.
Reply With Quote
  #2 (permalink)  
Old 16 Dec 2018, 07:09 am
Obsessed Cruiser
 
Join Date: Aug 2015
Location: Lake Wales, FL
Posts: 5,011
Default Re: P0123 Throttle Body Sensor Code

It could be a bad TPS, but if it were mine, I'd try cleaning the throttle body first. Have you EVER cleaned it?
podo2000 and oldthom like this.
__________________


Aspire to inspire before you expire.
Reply With Quote
  #3 (permalink)  
Old 16 Dec 2018, 12:28 pm
Fresh Cruiser
 
Join Date: Nov 2015
Posts: 8
Default Re: P0123 Throttle Body Sensor Code

Hello.

I have not cleaned the throttle body before.
Reply With Quote
  #4 (permalink)  
Old 16 Dec 2018, 01:51 pm
Obsessed Cruiser
 
Join Date: Aug 2014
Location: Thousand Oaks, CA
Posts: 7,473
Default Re: P0123 Throttle Body Sensor Code

P0123 - Throttle Position Sensor Circuit High Input:
Possible Causes:
1. Throttle Position Sensor sweep TP Sensor ground circuit is open
2. Throttle Position Sensor signal circuit is open or is shorted to VREF - 5 volts
3. Throttle Position Sensor is damaged or has failed
4. Possible intermittent condition
5. PCM has failed

I would suggest first checking the TPS plug and the wiring going to it. Wriggle the wires and see if the rpm's change.

Did you reset the DTC's when you were at Autozone? And did the same codes come back?

For the P0733 code when was the last time the transmission oil and oil filter was changed? Check the transmission fluid level?
__________________
If at First You Don't Succeed - Try, Try Again

Last edited by ptcruisersteve; 16 Dec 2018 at 05:27 pm.
Reply With Quote
  #5 (permalink)  
Old 16 Dec 2018, 06:25 pm
RickinPA's Avatar
Cool Cruiser
 
Join Date: Jun 2014
Location: southeastern PA
Posts: 360
Default Re: P0123 Throttle Body Sensor Code

If it were mine, I'd:

Clean the throttle body. I do this once a year on our cars. My understanding is that the throttle bodies can be sensitive to dirt build-up at idle speeds. I usually moisten a clean wiper with throttle body cleaner and wipe off the throat and plate of the throttle body as best I can. Then I spray the throttle body cleaner through the throttle body with the engine running, trying to avoid spraying the shaft where it enters the TPS. I don't think it will fix the problem, but it should be done.

I'd disconnect the electrical connector on the TPS and make sure all the pins and sockets looked OK. I'd tug medium gently on each wire, if it has "give" the wire could be broken at the connector. Fix if necessary. Then reconnect it and make sure it was properly seated. There's usually a locking tab on the connector you have to figure out. Probably not the cause, but it doesn't cost anything to try.

Then I'd run it for a bit and see if the code reoccurs.

If I got another TPS code, I'd replace the TPS. They're not too expensive and not to hard to replace.

Then I'd run it for a bit and see if the code reoccurs.

If I got another TPS code, I'd dig into the wiring. The TPS has three connections on the PCM; a 5 volt supply (from PCM), a ground (from PCM), and a signal (to PCM). The TPS is a variable resistor. As the position of the throttle plate changes it moves the wiper contact in the variable resistor. This causes the signal voltage to swing between ~1 volt and ~4 volts. The PCM reads the signal voltage to determine the position of the throttle plate. Checking wiring involves determining where each wire goes, connector-to-connector, and checking their conductivity with a multi-meter. Likelihood of wiring problem, probably low, but it does happen.

Been down this road on my daughter's '04 Neon. It ended up being a broken wire deep in the wiring harness. I had to dig through a bunch of schematics to figgure out how the three wires were routed, turned out each wire took a seperate meandering path to the PCM, and to top it off each wire went to a different connector on the PCM. I'd bet this problem was why the car was turned in for resell. I found evidence someone before was checking wiring, but they didn't dig deep enough. In the end I bypassed the broken wiring, and the random, but persistent, TPS code went away.
chuzz likes this.
Reply With Quote
  #6 (permalink)  
Old 16 Dec 2018, 09:31 pm
Fresh Cruiser
 
Join Date: Nov 2015
Posts: 8
Default Re: P0123 Throttle Body Sensor Code

Thanks for all the suggestions. Can the Throttle Body be cleaned without removing it from the car?
Reply With Quote
  #7 (permalink)  
Old 17 Dec 2018, 04:43 am
RickinPA's Avatar
Cool Cruiser
 
Join Date: Jun 2014
Location: southeastern PA
Posts: 360
Default Re: P0123 Throttle Body Sensor Code

Quote:
Originally Posted by cejordi84 View Post
Thanks for all the suggestions. Can the Throttle Body be cleaned without removing it from the car?
Yes. On my '01 PT I have to remove the vanity cover (I think they deleted it on later years), it just pops off. There's a rubber bellows between the air filter box and throttle body. There is an an air temperature sensor on top of the bellows and a plastic hose on the underside of the bellows that have to be removed, a bit stiff but they pull out. There are two clamps on each end of the bellows that need to be loosened. The bellows can be removed by compressing it. It takes a little effort. Note the alignment tabs on the bellows for reassembly.

My throttle body is mechanically cable operated. I think the later model PTs use the same system (somebody correct me if I'm wrong). The throttle plate can be opened by twisting where the cables connect.

For cleaning I usually moisten a fresh clean paper towel with throttle body cleaner, open the throttle plate and wipe all the surfaces I can get to, until they're clean. If there were stubborn deposits, I'd use a simple tooth brush (not one of those with the fancy bits of rubber in the bristles or on the head), and scrub the deposits off with throttle body cleaner. Then wipe the loosened deposits out with a clean paper towel.

Then I'd start the engine and spray into the throttle body while reving the engine a bit by opening and closing the throttle plate.

After shutting off the engine, reinstall the bellows (noting the alignment tab), snug up the clamps securing it, reinstall the air temperature sensor, reinstall the plastic hose, and reinstall the vanity cover. Good to go. It's not hard.
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Bad throttle body? phraxion Tech & Performance Forum 6 24 Nov 2013 03:34 pm
Do I need to change sensor/s on my 5-speed..got auto throttle body shelbyzman Tech & Performance Forum 3 26 Jun 2013 04:52 pm
Throttle Body Jimmy2011 Turbo Performance 4 27 May 2012 06:29 pm
P0123 Throttle Position (TP) Sensor Circuit High Voltage stan6406 Tech & Performance Forum 5 22 Feb 2012 07:30 pm
looking for a throttle body....................... rockrtboy Classifieds: Want To Buy 2 09 Jun 2007 11:44 am


All times are GMT -5. The time now is 11:36 pm.




Powered by vBulletin® Version 3.8.2
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
LinkBacks Enabled by vBSEO 3.6.0 PL2 © 2011, Crawlability, Inc.
vB.Sponsors