Throttle position sensor problems

[Dales85]

Hi all bear with me im new on here. So not sure if this has already been talked about. I have a problem with my a4 b6 1.9tdi theres a warning light on and flashing coil light on dash. Snap on has brought up throttle position sensor short i think it said. Il have to get the code. But theres no throttle as you could imagine. Idles at about 1150revs in limp mode. I did have water issues about a year ago with ecu box the bottom was full of water. Ive eliminated that with holes at bottom of box draining water. Then theres the floor gets wet in the car when rains. Ive also sorted that by cleaning all the crap under battery and brake servo and geting rid of the gromets. I cleaned all the wirring out with wd40 contact cleaner and to be honest the only thing that looked bad was the fan relay which i cleaned up but will replace. I bought a second had throttle pedal but came back as a petrol one which i didnt think mattered. When i start the car it seems fine soon as i press the throttle the revs drop and then goes into safe mode i guess.

[Stevey Y]

Hi the TPS sensor is attached to the pedal, a bit fiddly to remove but once off go buy another with the same part number as your old unit, diesel TPS are different from petrol as the wiring connector is the same but the wires are pinned in a different sequence.

Steve.

[Dales85]

Yea ive tried a petrol one but it didnt work suppose a il have to get a diesel one. Ive seen the hella ones on eBay. I may phone around spares and see if i can get a second hand one to save some money. Do you know if theres different types of tps on diesel models reason i ask if i phoned and said what year the car is being a b6 body would the diesels all be the same?

[Dales85]

18 hours ago, Stevey Y said:

Hi the TPS sensor is attached to the pedal, a bit fiddly to remove but once off go buy another with the same part number as your old unit, diesel TPS are different from petrol as the wiring connector is the same but the wires are pinned in a different sequence.

Steve.

Hi steve the wirring i havent changed on my car mind its the same one. And looking at both the throttle pedals they just look like 6 pin connections which look identical mate.

[Stevey Y]

5 hours ago, Dales85 said:

Yea ive tried a petrol one but it didnt work suppose a il have to get a diesel one. Ive seen the hella ones on ebay. I may phone around spares and see if i can get a second hand one to save some money. Do you know if theres different types of tps on diesel models reason i ask if i phoned and said what year the car is being a b6 body would the diesels all be the same?

Hi thats why I suggested you get the number off of your old part, the petrol version will have the same plug but the wires may be a different con figuration  to the diesel and still use six pins, they should be able to match the part from your registration/VIN but another thought has occurred to me is the throttle body clogged up with carbon as that would cause a code for the TPS my daughters car showed the same code but on closer inspection it turned out to be the throttle body as it was covered inside with carbon and was having trouble moving the butterfly so I changed it did a readapting of the new valve scrubbed the code and its all good.

Steve. 

[Dales85]

1 hour ago, Stevey Y said:

Hi thats why I suggested you get the number off of your old part, the petrol version will have the same plug but the wires may be a different con figuration  to the diesel and still use six pins, they should be able to match the part from your registration/VIN but another thought has occurred to me is the throttle body clogged up with carbon as that would cause a code for the TPS my daughters car showed the same code but on closer inspection it turned out to be the throttle body as it was covered inside with carbon and was having trouble moving the butterfly so I changed it did a readapting of the new valve scrubbed the code and its all good.

Steve. 

Genius mate i didnt think of the throttle body be worth a shot tomoz. The egr was nackered when i done a delete and had the car remaped earlier last year. Im gona order the tps tomorrow ive found one with the correct number. And il strip the throttle body down tomoz and use some egr cleaner on it after inspecting. Cheers steve mate thanks a bunch with the advice appreciate it. Will get get when throttle body is done maybe some pics. Also when the tps comes. Now to find the location of the throttle body. 🙂

[Dales85]

5 hours ago, Stevey Y said:

Hi thats why I suggested you get the number off of your old part, the petrol version will have the same plug but the wires may be a different con figuration  to the diesel and still use six pins, they should be able to match the part from your registration/VIN but another thought has occurred to me is the throttle body clogged up with carbon as that would cause a code for the TPS my daughters car showed the same code but on closer inspection it turned out to be the throttle body as it was covered inside with carbon and was having trouble moving the butterfly so I changed it did a readapting of the new valve scrubbed the code and its all good.

Steve. 

Steve just saying you know its a diesel i got rite... They havent got a throttle body have they?? Also i havent got a egr valve as its been deleted with remap

5 hours ago, Stevey Y said:

Hi thats why I suggested you get the number off of your old part, the petrol version will have the same plug but the wires may be a different con figuration  to the diesel and still use six pins, they should be able to match the part from your registration/VIN but another thought has occurred to me is the throttle body clogged up with carbon as that would cause a code for the TPS my daughters car showed the same code but on closer inspection it turned out to be the throttle body as it was covered inside with carbon and was having trouble moving the butterfly so I changed it did a readapting of the new valve scrubbed the code and its all good.

Steve. 

Genius mate i didnt think of the throttle body be worth a shot tomoz. The egr was nackered when i done a delete and had the car remaped earlier last year. Im gona order the tps tomorrow ive found one with the correct number. And il strip the throttle body down tomoz and use some egr cleaner on it after inspecting. Cheers steve mate thanks a bunch with the advice appreciate it. Will get get when throttle body is done maybe some pics. Also when the tps comes. Now to find the location of the throttle body. 🙂

[Stevey Y]

Hi Dale if you follow the pipe for the EGR the throttle body will be just below where the pipe goes into the manifold, the throttle body has a wiring connector on it, just be careful when cleaning  as the drive gears are plastic and the teeth are easily damaged they do an upgraded refurb kit for them so it might be worth looking in the control/gearbox to see what yours are like.

Steve.

[Stagn8]

Got me confused here Steve, why does a diesel need a throttle body? Surely throttle control is done directly via the ecu and injectors. The position sensor on the accelerator send its position to the ecu and the ecu increases or decreases fuel accordingly. 

[Dales85]

4 minutes ago, Stagn8 said:

Got me confused here Steve, why does a diesel need a throttle body? Surely throttle control is done directly via the ecu and injectors. The position sensor on the accelerator send its position to the ecu and the ecu increases or decreases fuel accordingly. 

Thats exactly what i was thinking i thought diesels are more or less controled via injectors more fuel less fuel sort of thing.

[Dales85]

30 minutes ago, Stevey Y said:

Hi Dale if you follow the pipe for the EGR the throttle body will be just below where the pipe goes into the manifold, the throttle body has a wiring connector on it, just be careful when cleaning  as the drive gears are plastic and the teeth are easily damaged they do an upgraded refurb kit for them so it might be worth looking in the control/gearbox to see what yours are like.

Steve.

Ok cheers steve il follow this up and the advice. After all i did ask for this 😊 the tps is on its way too. Il see what this throttle body looks like tomorrow and strip it down to see 

[Stevey Y]

7 minutes ago, Dales85 said:

Thats exactly what i was thinking i thought diesels are more or less controled via injectors more fuel less fuel sort of thing.

Nope they all need air and the injector cycles are all controlled by that valve, open the butterfly to allow in more air the injector pulse for longer to match the air ratio in coming, shut the valve means less is being injected because of the lower airflow in coming.

Steve.

[Stagn8]

H’mmm interesting, every day is a school day.
I guess the air fuel ratio has to be controlled in some fashion and this would be a simple way of doing it and of course that is how it is done with petrol engines. Don’t know why I thought it was different as both fuels now use direct injection for precision and both have a need to keep the mixture correct.

[Dales85]

Hi all just a update new tps came yday. I fitted it and problem solved now. I cleaned all the plugs and wirring looms plus terminals from ecu cover to dash board side with electric contact cleaner and job done. Also the culprit was a ecu tray full of water last year which i drined out and solved by drilling holes in the bottom of it. Also all my plenum chamber drainage holes were blocked and full of crap causing water to come in and wetting the carpets ect. So defo do this even if you havent got problems ok itl save you in the long run. 🙂 big shoutout to Steve on this forum hes been a great help with advice and great communication 😊 all the best

[Stevey Y]

4 hours ago, Dales85 said:

Hi all just a update new tps came yday. I fitted it and problem solved now. I cleaned all the plugs and wirring looms plus terminals from ecu cover to dash board side with electric contact cleaner and job done. Also the culprit was a ecu tray full of water last year which i drined out and solved by drilling holes in the bottom of it. Also all my plenum chamber drainage holes were blocked and full of crap causing water to come in and wetting the carpets ect. So defo do this even if you havent got problems ok itl save you in the long run. 🙂 big shoutout to Steve on this forum hes been a great help with advice and great communication 😊 all the best

Hi Dale I am glad to have helped and the fact is the problem is solved, we got there in the end, trying to auto diagnose problems can be super difficult as both Gareth and Steve Q will bear witness, they have both given very precise information based on only half the information about the problem from whoever posted the problem and then being told they are wrong, its a thankless task sometimes but hats off to them they still keep trying, your info has been very good and I thank you for that.

Steve.