Alfa 156 motor control system failure - TR
I have an Alfa 156 2.0 JTS and it's fantastic. However, there is a recurring problem that the dealer doesn't seem able to rectify. On 6 occasions in the last year the information read out on the dash displays 'motor control system failure - go to dealer' and the rev limiter cuts in at 3000 revs. The ECU has been replaced as has the throttle potentiometer and various electrical connections, but it still happens, intermittently.

Any suggestions would be appreciated.
alfa 156 motor control system failure - teabelly
This article seems to suggest that it is a problem with petrol quality:

Had you filled up somewhere different just before it displayed the message? Other than that it could be the gizmo that detects whether it likes the petrol or not playing up.
alfa 156 motor control system failure - TR
Thanks for the suggestion.
I use Shell Optimax, on the advice of HJ, and can't recall any occasion when it could be linked to a fill up. The only constant is that it usually happens when accelerating from low speeds in first or second gear.
alfa 156 motor control system failure - Aprilia
I heard the AFM's are a weak spot on these.
alfa 156 motor control system failure - David Lacey
That fault must be a nightmare for the Dealership workshop to sort out.......
alfa 156 motor control system failure - TR
Thanks for the suggestion and please excuse my ignorance, but what is an AFM?
alfa 156 motor control system failure - Tck
I have the same - or at least similar - problem with my 156 JTS. I get the failure message, but without the rev limiter cutting in early. It was diagnosed first time as a knock sensor failure, replacement of which cured it. For 4 weeks.
I now get it intermittently and the dealer reckons it's the same thing but wouldn't be drawn on whether there might be an underlying problem or simply repetitive component failure. I suspect the latter.
Good Luck!
alfa 156 motor control system failure - TR
Thanks for your reply, TCK. It's a relief to know that someone else has the problem as well! I wouldn't mind so much if the rev limiter didn't keep cutting in, but that completely scuppers any progress I try to make. The dealer's done his best but no one else in ARGB is interested. It's a shame because in every other respect the car's fine. if your dealer does eventually find the cause, pls let me know; I'll do the same.
alfa 156 motor control system failure - PR {P}
Try filling with 95Ron unleaded, see if the problem persists. Also you could try someone there may help also
alfa 156 motor control system failure - alfa2007
Hi there, mine is a alfa 156 1.6 TS. i am having exactly similar problem as yours. Have you sorted this out. please let me know asap if you had found a solution to this problem. This could save me a lot of time and money and moreover reduce my stress level. pls. cheers,
alfa 156 motor control system failure - Collos25
The engines were not designed to run on Optimax,its more than likely the knock sensor as stated above.The ecu is mapped to run on normal petrol.
alfa 156 motor control system failure - Red Baron

I have the 1.6TS engine and have used Shell Optimax (V-power) and have never had a problem. In fact, I experience less hesitancy in the engine from cold start if I use the higher grade petrol.

Knock sensor...maybe, but critically at 3000 rpm the timing is advanced and more oil is fed into the top of the engine.
alfa 156 motor control system failure - buchanan17
Yep - I filled up for the very first time with Optimax and 300 miles later the lambda sensor packed in. Seems like too much of a coincidence.... Got the lovely "motor system conrol failure" message....

alfa 156 motor control system failure - TR

This problem is nothing to do with the grade of petrol used. The car will run perfectly on normal or Optimax.

The solution was found by one of the mechanics at Reg Vardy in Leicester. There is a junction box where all the control lines converge; the cables being attached with push clips or spade connectors. The mechanic soldered all the connectors to their relevant terminals and the car has been utterly brilliant ever since.

It's a simple cure to a really frustrating problem and something Alfa dealers should know about. The problem is that most of them can't be bothered to do a detailed investigation or are employing people who are fitters, not technicians or engineers.

Don't give up - once the problem is solved you can get back to having a beautiful car that puts a smile on your face every time you drive it!

alfa 156 motor control system failure - Sportivo
I've had the same ongoing fault on my '03 156 JTS SW - it happened again on the way to work this morning..

Initially it was traced to the known problem of the connecting block next to the exhaust manifold - this was soldered under warranty. It was OK for about a year but then it happened again - we are probably into double figures now. On each occasion the engine goes into protect mode - but if the engine is stopped and re-started, this can normally be cleared although the light / beeper still shows.

Its been back to both dealer and independent and each time the computer says throttle is the cause and the garages have generally suspected faulty connections. Normally a reset solves the problem but of course this does not get to the root - last time we had the throttle sensor replaced, more out of lets try something than we know exactly what's wrong. On one occasion, I got a REAL fault (blown coil) but it was quite apparent that something really was wrong on that occasion (running on three cylinders!).

Ultimately its not really been much of a problem (except on the occasion that my wife had the car and it wouldn't reset, she panicked) but it really is a pain taking it on an 80 mile round trip to the get it reset every time it happens.

I have two questions:
can fault code reading machines you can buy reset the computer or do they just give you the fault code (!) - having one that could would save a drive to the garage.
I'm interested in the junction box TR mentions - which one is it?
alfa 156 motor control system failure - mfarrow
Has anyone tried to re-solder the connections in this junction box for you Sportivo?

Soldered connections aren't the strongest of joints, especially if they're subject to heat un/loading and vibration. Tiny cracks can appear in the solder which can't be seen easily by the naked eye, but spoil the connection.

Mike Farrow
alfa 156 motor control system failure - adverse camber
google for alfadiag - pc diagnostics for petrol alfas. is quite a good forum
alfa 156 motor control system failure - Sportivo
I've now disconnected the battery (for 20 mins) to clear the fault message - I'm pretty sure it's a false alarm but I'll wait to see it it happens again.


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