No speed signal to ecu

Hi all i have a 1.6 petrol sx auto on a 08 plate the problem is the car has been standing for some 6 months and everything was fine when it was parked up.

Tried to move the car today started first time however once in gear it will not move unless you rev the hell out of it and then it moves a little.

I have put the car in N and it rolls freely so the brakes are not stuck on and it shows the gears on the dash and you get the click when you put your foot on the brake.

I did notice some oil below the gearbox so not sure if there's a leak so put the car on lexia and the only fault on the gearbox is a temp one of no speed signal to ecu ?

Looked around and most people say crankshaft sensor but the car runs fine other than the gearbox

So does the gearbox have its own sensor ?? help really needed Thanks

I'd check the level of oil/fluid in the gearbox. Do you think the oil you found under the gearbox is engine oil or transmission fluid?

put the car on lexia and the only fault on the gearbox is a temp one of no speed signal to ecu ?

Can you say what the code is that went with the description, lexia will give a 'P' code and 4 numbers.

Delete the temp code and try running it again, then check for codes again.


Its definitely an automatic and not a sensodrive flappy-paddle clutch assisted semi auto gearbox?

C3driver52 wrote:

put the car on lexia and the only fault on the gearbox is a temp one of no speed signal to ecu ?

Can you say what the code is that went with the description, lexia will give a 'P' code and 4 numbers.

Delete the temp code and try running it again, then check for codes again.


Its definitely an automatic and not a sensodrive flappy-paddle clutch assisted semi auto gearbox?

I will put it back on lexia to check the code, i did delete the fault but as soon as i started the car it popped right back up again.

It has no paddles but it may well be a sensodrive as it can be fully automatic or you can use the gearstick to go up/down the gears

Missing Lincs wrote: Missing Lincs


Post subject: Re: No speed signal to ecu

It was under the box but as the car has been standing for 6 months no idea if its oil or transmission fluid

t.williams8 wrote:

Missing Lincs wrote: Missing Lincs


Post subject: Re: No speed signal to ecu

It was under the box but as the car has been standing for 6 months no idea if its oil or transmission fluid

I appreciate you have a fault code, that could have been there before the car was parked. An autobox which is down on fluid will behave just like yours is. As you said you found oil under the gearbox, my first check would be oil levels.

It has no paddles but it may well be a sensodrive as it can be fully automatic or you can use the gear stick to go up/down the gears

Its worth finding out which style of box it is as they have very different mechanicals. One has a clutch and one has a torque converter.


This is the gear selector (gear stick) for the sensodrive - its a manual gearbox with an electrically operated clutch plate
and this is the 'classic' gear selector from an AL4 fully automatic (PRND)

Tried to move the car today started first time however once in gear it will not move unless you rev the hell out of it and then it moves a little.

I think the sensodrive will do this with a worn or contaminated clutch plate

C3driver52 wrote:

It has no paddles but it may well be a sensodrive as it can be fully automatic or you can use the gear stick to go up/down the gears

Its worth finding out which style of box it is as they have very different mechanicals. One has a clutch and one has a torque converter.


This is the gear selector (gear stick) for the sensodrive - its a manual gearbox with an electrically operated clutch plate

sensodrive-gear-selector-citroen-c3.jpg

and this is the 'classic' gear selector from an AL4 fully automatic (PRND)

PRND_AL4_Citroen_C3.jpg

Tried to move the car today started first time however once in gear it will not move unless you rev the hell out of it and then it moves a little.

I think the sensodrive will do this with a worn or contaminated clutch plate

Many thanks it looks like a fully automatic one, as for the fault code it was cleared and comes back on again as soon as the car is started

t.williams8 wrote:as for the fault code it was cleared and comes back on again as soon as the car is started

Thanks, it would be good to know this bit of information:

C3driver52 wrote:Can you say what the code is that went with the description, lexia will give a 'P' code and 4 numbers.

Missing Lincs wrote:An autobox which is down on fluid will behave just like yours is. As you said you found oil under the gearbox, my first check would be oil levels.

Sounds like a sensible way forward.


If you are topping up the gearbox fluid, this post has information on the correct grade of transmission fluid for the AL4 gearbox
https://citroenc3owners.com/c3-automatic ... n-t56.html

Thanks for the help i will have to wait until the weekend to get the codes as its a mate doing the testing.

I know it said no speed signal to ecu but did not take notice of the code !! doh and the car is a fully automatic.
Also there is no snowflake etc showing on the dash for a fault