I'm having some problems with the throttle body on my 1.6 stilo. Basically the intake valve does not open when accelerating. I've checked and cleaned all the contacts on N75 and M10B connectors. I've checked the 5V supply between pins 5 and 1 on N75 and also checked that the feedback from throttle body is working ok with an ELM327 interface when manually opening intake valve.

Between pins 3 and 4 on throttle body, which are the input pins for the motor, i've measured the resistance and i get 0 (also with N75 connector unplugged). I guess this must be the problem since any voltage applied on these pins to get the motor to open the valve will not do anything.

Does anyone know what could be causing this ? Could the motor be dead or just the electrical tracks shorted ? I've opened the throttle body to have a look at the electrical tracks but could not get to them since they are enclosed in a plastic cover.

Resistance through the electric motor should be close to zero so that's not a short circuit, that's normal

What fault codes are you getting?

What symptoms?

"Basically the intake valve does not open when accelerating"

If the throttle valve didn't open you wouldn't accelerate at all

Does it start? Run? Idle? Accelerate?

Did it ever work correctly?

The error codes are P1687 and P1220 (similar to h ttp://www.fiatforum.com/stilo-technical/146070-stilo-fault-codes-1684-1687-1220-a.html) and the car runs in limpmode. Also been getting U1700 (can bus fault) and P0468 (fuel level sensor malfunction).

The car runs but with very little power, can just about get it do to 20mph . I've bought the car at an auction :bang: about two weeks ago so i don't know how this problem developed, at least the car was cheap.

With the N75 connector plugged in i can rev the engine up to 3000rpm, so at least it shows the problem is not between the accelerator pedal and ecu. With the N75 connector unplugged the engine idles, which i suppose it's because there is no feedback from the throttle body to the ecu.

I've cleaned all the contacts, cleaned the throttle inlet valve and did a throttle relearn but still running in limpmode. I'll probably just have to bite the bullet and buy a new throttle body, or take it to a fiat dealer. Any suggestions to what the problem might be will be really welcome. Thanks

Always difficult to diagnose from a distance but i'd firstly disconnect the air con linear pressure switch to take it out the system as it's on the same same 5v supply as the throttle body. The fact you have checked the 5v at the throttle body would tend to eliminate it but the clearer the system the better

U1700 shows can bus comm problem between NBC to NCM that's NBC nodes body computer to the ecu (NCM node motore controllo) so I'd check out the D4 connector as you haven't mentioned that yet

I bump this when I have the same problem and have searched the forum for days without an answer. I have a Stilo 1,6 -02 that is in "limp mode" with the fault codes P1220 and P0460. I have checked the most possible things but nothing works. Can anyone help?