Hello everyone,

a couple of months ago my car started having loads of problems: the car turned off while driving, sometimes it won't start and so on. At first it looked as a classic IC problem from what I was able to read. Popped the old one out, put a used one in (I wasn't sure it was working tho) and tried pairing the keys (the ones I got with the car) with Forscan. Pairing went smooth while initializing the module on Forscan fails and thanks to that, car won't start. Tried to check with the multimeter and the HS bus circuit from the obd looks ok (it reads 61 Ohms). Since I'm an idiot I deleted the paired keys to the old IC (thinking that I changed it) so I can't put it back to have a somehow working car which means that now is stuck in my backyard.

My bad is that I didn't read the DTC errors initially before doing anything and now I realized that there are plenty of errors related to the PCM. 

I summarize them here (they're in Italian unfortunately, I'll do my best to translate them)

===PCM DTC U0155-21===Codice: U0155 - Comunicazione mancante con il modulo di comando quadro strumenti (missing comms with the IC)

===PCM DTC P193B-24===Codice: P193B - Accelerator pedal signal

Il messaggio CAN dal quadro strumenti è assente. (Missing CAN message from the IC)

===PCM DTC P1936-24===

Codice: P1936 - Guasto circuito entrata interruttore frizione (Broken clutch circuit i think I don't even know what does it mean in Italian)

===PCM DTC P1935-64===

Codice: P1935 - Segnale interruttore/sensore freni (Signal brakes sensor)

===PCM DTC P1621-64===

Codice: P1621 - Le parole in codice dell'immobilizzatore non corrispondono. (Immobilizer passwords don't match)

===PCM DTC P0645-64===

Codice: P0645 - Circuito relè frizione aria condizionata (Broken A/C electrical circuit)

===PCM DTC P0380-21===Codice: P0380 - Circuito di controllo candelette di preriscaldamento (Broken glow plugs preheating circuit) circuit.

After that there are U1900 errors (missing CAN comms) with ABS and EPS and then some errors related to the IC not being paired. 

Any idea on what to do? Honestly I feel hopeless, I'm starting to think that the PCM is failing.

21 minutes ago, a_kole said:

Any idea on what to do?

Get an Auto-Electrician to sort it out before you turn the car in to a permanent giant paperweight.

9 hours ago, unofix said:

Get an Auto-Electrician to sort it out before you turn the car in to a permanent giant paperweight.

Hi and thank you for your reply.

Actually that's the first thing I did and I was quoted 1400€/1500€ (depending on who I asked to) to fix the issue and it is too much on a 270.000km car. The car is too old to justify the expense and given the situation I'm trying to fix it at home. So anything that's not that expensive it's good, otherwise I will just replace it (just as sad, it's been a great car with crazy memories).

@unofix If he got the original IC properly repaired, and put it back in, would that not give him a fighting chance to get the car back, or has he done so much with the new IC it's pointless?

3 hours ago, StephenFord said:

If he got the original IC properly repaired, and put it back in, would that not give him a fighting chance to get the car back, or has he done so much with the new IC it's pointless?

That's a hard one to give an exact answer on. The best chance of getting out of this mess would indeed be to have the original instrument cluster properly repaired. Then using FORScan programme the IC accept the ignition keys and keep the immobiliser happy.

Most of those DTC's posted are to do with communication errors caused by the IC. The one error that I can see which is unlikely to be related to the IC is the issue with the glow plugs which would not stop the engine from starting (perhaps just make  it a little bit rough on start up).

DTC's relating to the PCM are again probably being caused by communication errors on the canbus caused by the instrument cluster. In the UK I'd expect that a decent Auto-Electrician would be able to sort it all out in around 3 hours at a cost of £300 but perhaps things are much different in Italy ?