Jump to content

The RennTech.org community is Member supported!  Please consider an ANNUAL donation to help keep this site operating.
Click here to Donate

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)

Dreaded CEL today

Recommended Posts

I hate posting this. I got the dreaded CEL today. Car barely started. Drove around a little running errands, stopped, drove some more, stopped, and eventually the light turned itself off.

Idle was jumping all over the place, but eventually settled down.

Car has no power on acceleration.

I think it's MAF, which was recently cleaned on a routine LOF service.

Could it be the e-gas throttle, foot peddle?

I put on the Durametric and here are the codes:

P1101 Porsche fault code 594, input variables charge measurement

P1502 Porsche fault code 412, DVE fault during spring test

P1511 Porsche fault code 543, Throttle adjuster Environment condition not OK

P1120 Porsche fault code 117, Throttle Plate

P1122 Porsche fault code 431, Throttle potentiometer 2

Does anyone have any ideas? Seeing great Indy tomorrow. Thanks.

Link to comment
Share on other sites

  • Admin

P1101 Input variables, charge measurement - below limit, above limit

Possible fault cause

- Heavily soiled throttle
- Throttle damaged
- Mass air flow sensor

P1120 Throttle Valve – Signal Implausible

Possible fault cause
- Open circuit or short circuit in the wiring
- Throttle position sensor faulty
- DME control module faulty

P1122 Throttle position sensor 2 - signal implausible, below limit, above limit

Possible fault cause
- Open circuit in wiring
- Short circuit in wiring
- Throttle position sensor faulty
- DME control module faulty

P1502 Throttle jacking unit, spring test - above limit

Possible fault cause
- Throttle part

P1511 Throttle jacking unit - abortion of test due to negative influence on ambient condition

Possible fault cause

- Starting the vehicle during adaptation after replacement of throttle part
Do you see the common trend in these codes?
Throttle body and throttle body sensor/jacking unit.
Perhaps start with a through cleaning of the throttle body, butterfly, and the inspection and cleaning of the electrical connections.
Link to comment
Share on other sites

CEL turned off on its own yesterday. Car running strong as if CEL had never come on and reported symptoms had not occurred.

Situation untrustworthy at best.

MAF replacement and thorough cleaning scheduled next week.

Loren, your reply most appreciated. Mike Renzi in Fort Bragg picked up throttle issues right away. We'll get it all cleaned out. Replacing MAF just because.

Link to comment
Share on other sites

  • 4 years later...

I have a 2003 996 C2 convertible, manual, 124000km

I have had several problems over the past few months.  My electrical system appeared to be half on, AC fan would not run, no head lights, until I jiggled the ignition switch.  I replaced the ignition switch (noticed it was cracked) and resolved that problem. 

The car would cut out at idle.  I had a cam sensor error, so I replaced both. 

Now the car is intermittently unresponsive/sluggish.  Over the past few years the car would become unresponsive or run real rough at start up.  I would remove the throttle body, clean it and the car would run great again.  I recently had more serious problems where the car was stopping at idle and would not respond at all.  Then I got 4 codes when I tried to start it. P1502, P1517, P1120, P1122.  Cleared these ran ok, then became unresponsive again, feels like it will die at idle if I don’t give it gas.

My gut is telling me I have to replace the throttle body based on the following:

  • Age of the car

  • History of having the same symptoms and cleaning the TB to fix it. 

  • TB is clean now but still having problems



    Do you think replacing the TB makes sense as a next move?


    When I look up the TB part online, I see a Throttle Position Switch listed as a related part. Could this be the problem?   The part is about 1.5”x1.5”x3/8” with a rotary connection for a spindle.  I can’t find it on the engine and can’t see any reason for it as it appears the TB is a completely integrated assembly with the sensor built in.  Is this part of the gas pedal? My car is a 2003.  Was there an earlier version with a mechanical throttle that this is for?


    I found this older thread with the same error codes so I posted this here.  I would appreciate any help you can offer.




Link to comment
Share on other sites

Your car has e-gas so the throttle position sensors (there are two inside) are integrated into the throttle body.

I would reset the DME (reset the CEL), then do a e-gas throttle calibration first - turn key to last position before crank and leave the key there for 60s, then turn the key to OFF position for 10s and you're done. Do not touch the gas pedal during calibration.


I suspect though there is something wrong either with the wiring or the throttle body itself. Do you have a Durametric? If you do, you can monitor the reading of the two sensors inside the throttle body.


The sensor you showed above is for cabled t-body, not for your car.

Link to comment
Share on other sites

Hi Ahsai.  thanks for the feedback.  I should have said this in my original post... Yesterday I reset the CEL and did the throttle calibration.  Afterwards, I checked the throttle position sensor target vs actual on my Durametric and everything appeared to be in sync ie actual = target.  I think this is the test you are referring to.  The car ran ok for a 5-10 miles then started acting up again.   I will check out the Bosch part.  hopefully its not the wiring.  


thanks for the clarification on the other sensor!



Link to comment
Share on other sites

1122 refers to sensor 2 inside the t-body so it may be the one acting up. If memory serves, Durametric can display the readings of both sensors and the reading of one sensor is always half of the reading of the other sensor. Perhaps with key ON engine OFF, you can move the pedal for its full range back and forth a few times and see if the sensor 2 reading make sense. Maybe you can catch a glitch that way.

Link to comment
Share on other sites

So I replaced my throttle body on the weekend and did the reset on it, started it up. Ran great for 2 days. 

Last night on the way home the idle started to drop off then jump up and stabilize, but the car was still responsive.

This morning started ok, idled a little rough, then after a few 100 meters the unresponsiveness started up again.

Same exact problem I had before.  Items replaced to date: ignition switch, cam sensors and throttle body.


I would appreciate any input on possible next steps.


It must be something electrical/intermittent because it comes and goes?

Could it be my MAF sensor? gas pedal? ignition coil? fuel injectors? 

Is there a way to determine what is happening with my Durametric?

  • Like 1
Link to comment
Share on other sites

Wizard - I could not find any way on my Durametric to test Fuel delivery/pressure/pump.


I hooked up my Durametric last night and got similar errors from before I replaced the TB even though my CEL was not on.  (see pic below) 


I cleared the faults and it ran perfect.  Based on this result I will proceed with judgejon's suggestions and try cleaning the MAF and electrical connection tonight.


Based on the other posts I read, I also tried the PSM on/off when it was idling real rough but it made no difference.  I think to properly assess this idea I will need to clear all fault codes then drive with PSM off for a while.   I will try this if the MAF/electrical cleaning does not work.


Link to comment
Share on other sites

Belleriver. My apologies. I should have been more explicit. Hooking up the Durametric was meant for fault codes. 


From memory, Durametric does provide a MAF reading and short and long term fuel trims which may assist in diagnosing the problem if cleaning/replacing the MAF doesn't remedy it.


Has the fuel filter ever been replaced to your knowledge?



Link to comment
Share on other sites

  • 2 weeks later...
  • 4 months later...
On 5/18/2018 at 1:58 AM, belleriver said:

update: cleaned my MAF and electrical connection to TB.  running great for now...



Hi Belleriver, did the codes and symptoms come up again, I did exactly the same with you and replaced the TB 6 mths ago. Few day ago I did have some codes again, although this time the car would not dead and still drive-able  but I can feel the pedal response is weird.  Code:  (P1120 P1122 P1514)


And now I am thinking of the accelerate sensor under the pedal...



Link to comment
Share on other sites

I got the exact same symptoms 3300km (2000 miles) later, not as bad as before but i could feel it starting to happen. Cleaned my airfilter and maf sensor, problem gone. Sorry, I cant remember for sure but i dont think I got any codes. Im going to start cleaning mine every 2500km.   

Link to comment
Share on other sites

5 minutes ago, belleriver said:

I got the exact same symptoms 3300km (2000 miles) later, not as bad as before but i could feel it starting to happen. Cleaned my airfilter and maf sensor, problem gone. Sorry, I cant remember for sure but i dont think I got any codes. Im going to start cleaning mine every 2500km.   


Thanks for the update and seems we are at the same boat, could feel it started to happen, and ran around 3200km too, ummmm


I did clean the throttle connector, codes gone and feeling ok for now, will try to clean the contact of the pedal sensor connector as well too, maf remain at the moment. Will keep update.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.