Choice was limited on limp home mode!!

Stilo02dynamic16V said:

Choice was limited on limp home mode!!

Click to expand...

lol true !

Hi - dealership have been back in touch and are saying that a fiat tech has diagnosed the problem and that both throttle body and ecu need to be changed as a matched pair - is this true or are they pulling a fast one?
Many thanks

I have seen both components go down to be honest but I stand by most post (#6) as my first point of testing.

Ta for replying - I appreciate the problem is a new ECU - but does that mean it needs a new throttle body as well?
I'm just not sure it needs a new throttle body too - they've fitted the new one and have then diagnosed the ECU needs replacing - yet the new throttle body made no difference.

Well, never heard of a throttle body and an ECU ever needing to be "a matched pair". How is anyone going to change one of those items ever again if they always have to be replaced together. Compatible, yes, but a matched pair? Sounds like antiques roadshow. Maybe they mean that a new ECU needs a newer design throttle body

Are you paying for this or is this a warranty job? To replace a throttle body, it does nothing to repair the fault and then they say it needs replacing again with another one sounds novel and is ok as long as you're not paying for each one. What's the reasoning?

ECU needing replacement might well be needing to bite the bullet as you're between a rock and a hard place but check the car out thoroughly before paying any bills and driving it away

Hi Deckchair5 - they changed the throttle body, which made no difference, now are telling me they need to replace the ecu as well, so are saying both my throttle body and ecu were at fault. Car out of warranty as 02 plate so is at my cost. My feeling is that they're trying it on as wouldn't it make sense to try a recon ecu with my old throttle body? As it's a recon ecu they're going to fit is there any reason why it wouldn't be compatible with my old throttle body?

Well, if they wrongly diagnosed and replaced the throttle body and it does nothing to improve things then it would be logical and reasonable to ask for the old one to be put back. In reality, I think they may send the old one off on a sale and return as it's a reconditionable part so it may not be around any more. You'd have to check

I would think that all the 1.6 parts would be compatible and not need to be "matched". They do the "matching" with a throttle relearn procedure

Thanks for that - I've told dealership not to send either the old ecu or the old throttle body back until car is fixed and I give my say so. The old ecu won't perform (or complete) a throttle relearn, so surely that points to it being the ecu, or a component it tests during relearn - does it only test the throttle body, or does it test other components? As changing the throttle body made no difference, it points to the ECU. So does logic suggest trying the old throttle body with a recon ecu as a first try? Could the D4 connector be at fault, cruise control fault, or the accelerator potentiometer (does the relearn procedure check any of these?

Ta

Wow so many questions.
Well the throttle relearn is communications between the ECU and the throttle body and therefore also the communication lines in between. A bad connection or connector would cause just as much grief

Ref this drawing


The gas pedal comms go through the D4 connector to the ECU so imagine the D4 is between the gas pedal and the ECM as they call it here

Ta 4 the help Deckchair5 - I'm thinking the fave culprit is the wiring between the throttle body and ECU - where's the ECU sited as can't remember as car in dealership?

Ta

That's an easy one to find
Right of centre on top the engine with two large multi plugs.

M10A and M10B here

Ta - remember now! Have fingers crossed it's the wiring!

Hi all - problem sorted - it was the ecu - so have put the old throttle body back on - just for info fiat tech say if the throttle body goes you need to change the ecu and throttle body together - if its the ecu then can change only the ecu. Thanks for all the info and help - much appreciated - plus ecu has years warranty so hopefully no more fault codes!!

your welcome although I disagree with the 'fiat tech say if the throttle body goes you need to change the ecu and throttle body together'.

You can donate know

https://www.fiatforum.com/donations.php

"although I disagree with the 'fiat tech say if the throttle body goes you need to change the ecu and throttle body together'.
Yep me too. I've heard Lindsay Lohan come out with less dross

Glad it's sorted

Hi all - got car back Sat morn - took for drive today - did 60 mile, then engine fault - 1684 - limp home mode - exactly as before fiaqt dealership had it. Once home, (took hours) took connector off throttle body, checked continuity, put back on - car works fine - has faults stored so back to dealership tomorrow to give them hell - seems only fault has been bad connections in the 6 pin throttle body connection breaking down - does that seem reasonable?

Ta

I posted here (ages ago & I cant find it) about using a cable tie to hold up the throttle body loom as it is quite heavy/hangs down & puts strain on the TB connector. Also I assume a throttle learn was carried out after ecu fitted?

seems only fault has been bad connections in the 6 pin throttle body connection breaking down - does that seem reasonable?
Yes it does, see post 11 in this thread

hi - yes dealership said they'd done a throttle body learn - after I got home on limp home mode - I started the car in the drive, and just touched the throttle body connector and could hear like a crackling sound from the throttle body - unplugged and reconnected the throttle body and hey presto car running fine. Have 1684 and 1687 faults stored so will take back to dealership tomorrow and get them to put my old ecu back on and a refund - can of contact cleaner and a couple of cable ties and jobs a good un. Ta for help etc.