T4 V6 Caravelle ECU

[dub rat]

Hi Guys,
I have a 2003 Caravelle that is cutting out in this hot weather. I am pretty sure that it is the ambient temperature of the ECU, having replaced or checked the usual suspects. Can anybody let me know what is involved in changing the ECU out for a new one and do I need to use a genuine one, which will probably be really expensive.
Any help would be greatly appreciated, I really don't want to walk away from this van. Thanks.
Dub Rat.

[h100vw]

Have you scanned the ecu for faults. Probably get a clue about what's failing from that. A replacement ecu would need the immobiliser matching to the key and instruments. That would be the last thing I would be trying.

[Sunny43.5]

What are the symptons when it cuts out , does it just shut down and then mysteriolously start up again ? there is an engine relay in the T4,s that are well known for developing a fault . Mine use to cut out while driving and then a few minutes later would restart again , a lousy $25 relay was the problem .

[Tornado T5]

What are the symptons when it cuts out , does it just shut down and then mysteriolously start up again ? there is an engine relay in the T4,s that are well known for developing a fault . Mine use to cut out while driving and then a few minutes later would restart again , a lousy $25 relay was the problem .

Yes...you jogged my memory, my T4 would fail to start randomly and it was traced to one of the relays in the fuse box iirc....#30 relay

[Sunny43.5]

Yes it was pretty scary when it cut out in the middle of traffic , I had to use the starter to turn over the engine in gear to get it onto the footpath then wait for it to decide to start again .

[dub rat]

Hi Guys,
Thanks for all of the replies. The ECU has been sent away and tested, showing no faults. I have replace relay 30 with a new one and that has not cured the fault. Can anybody suggest another suspect relay or component that may be causing this issue. Thanks.
Dub Rat.

[h100vw]

CRank position sensors can cause random switch offs with no codes.

[dub rat]

If that is what they call the knock sensor, then yes it has already been replaced. I was really hoping that somebody here might have had an answer.
It only cuts out on warm days, during the winter there is no problem. Makes it an expensive seasonal car.
Cheers.

[h100vw]

Crank and knock sensors are different. The crank sensor tells the ecu the engine is rotating. Without it the ecu won't inject fuel or send the sparks

[LogicprObe]

Hi Guys,
Thanks for all of the replies. The ECU has been sent away and tested, showing no faults. I have replace relay 30 with a new one and that has not cured the fault. Can anybody suggest another suspect relay or component that may be causing this issue. Thanks.
Dub Rat.

My T4 wasn't a V6 but I replaced a few relays and it ended up being the coil that would only fail during hot, humid weather.
It looked fine and tested fine but replacing it cured the problem.
(it was a cheap item for the 5 cylinder anyway)