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Discussion Starter #1
i keep getting the cog light comeing on by the p/d/n/r sign in my automatic what is it for and why does it come on and then go out when car urned of then back on again plaease help
 

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You have a gearbox problem. I suggest you get the fault codes read asap to prevent damage. Codes can be read directly from the gearbox diagnostic port.
 

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Discussion Starter #3
so its not connected to the eml light at all whould theses codes show up with a diagnostic that is read from the port under the drivers wheel
 

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Discussion Starter #5
its a snapon one with lastest updaated software its been scanned loads at mo because got issues with eml coming on just waiting for a throttle sensor to be fitted because thats the code it showing up
 

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Discussion Starter #7
oh right so it could be linked to that

i take it that
2799 Abort DV-adaption because of enviroment
2786 Throttle-valve potentiometer 1

could be throwing on the eml and the cog also the antiskid and brake warning lights as when eml comes on the antiskid and brake light start to flash
 

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Was it DV or DK? DK is Drosselklappe - throttle plate.
When the throttle signal becomes unreliable it will cause the errors you see, and pass those on to traction control (which would do engine torque limitation by closing the throttle)

It all seems to tie in with the throttle signal though.
 

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Yep, it's a built in part.
It'll work using about 5 different inputs, 2 potentiometers in the pedal, and both are checked against each other for plausibility, ie they both have to independently give a matching %, despite having different scales.

Once the ECU is sure, it'll then move the throttle plate, using 2 potentiometers again to check not only the position, but to check the other potentiometer too. Yet again, these signals both have to match, and they are on different scales, so shorting both the wires wouldn't make it look like Wide Open Throttle.
It also then has a third virtual potentiometer which is the air flow meter signal. It has to get an airflow signal that also matches what the ECU would expect at whatever RPM and throttle angle.
It's a very clever system used by most manufacturers which is why the jammed throttle stories on Toyotas have to be taken with a pinch of salt.
In a few of those cases, CCTV has spotted the car shooting off whilst the owner swears they are braking, with no brake lights on
 

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Discussion Starter #12
well im fed up with waiting for the garage to change a throttle sesor can some one tell me from the codes which sensor as gone and how hard is it to change

2799 Abort DV-adaption because of enviroment
2786 Throttle-valve potentiometer 1
 
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