Faulty DFI module?

[tezza]

Hi everyone,

Can a DFI module in a 3.8lt Ecotec just die all of a sudden and not allow the car to start? There have been no problems with the starting and running of the car. Or should I be looking at other things?

[greenacc]

Hey Tez, DFi's can develope a mind of their own when they get old. I had 2 that died suddenly while driving along, the first one at 100 km/h which was quite an experience.

It will throw a code or 3, so check that before you go buying any parts. Probably somewhere around 46,47,48
They can be real headaches too, cos there can be hidden issues in other parts of the system that can keep blowing DFI's once in a blue moon.
When you get it started again leave it to idle for a good 10 min in your driveway to check it's not going to konk out again.

[scvs6]

Yes it is possible. I took off from a set of traffic lights, got up to about 30km/h then all the sudden the engine cut out and wouldn't start anymore. Luckly I just got it off the road, had to get it towed. Turned out to be the DFI Module.

EDIT: I knew it wasn't the fuel pump because it wouldn't run on petrol or gas.

[tezza]

Ok can DFI modules be tested at all, or is the easiest to get another one to try?

[scvs6]

Well the electritian at work had one with him that he uses to test to see if thats the problem. He came to work at put it on my car until I got a new one then I gave it back to him. I got the DFI Module, Coils, Spark Plugs and Leads as a set from Repco for $320. Just the DFI on its own from Holden was $450, and they sell the coils seperately.

[tezza]

So faulty DFI modules should throw up a code? I'll check it out.

[scvs6]

Mine didn't bring up a code. I ended up changing the crank angle sensor, harmonic balancer, some relays and was still not starting, changed the DFI Module and started straight away.

[commo tech]

If the dfi fails it will not log a code, the ecu isnt smart enough to recognise a fault in the dfi, but as the dfi is the link between the ecu and the crank angle sensor it may in some cases log a crank angel sensor code

[iwishmyVNwouldstart]

mate pretty common problem. check the connector from the harness, they can corrode and cause a bad connection leading to the no start.

I had the same problem, the connector was fouled up badly. I replaced the female connector on the engine harness side, scaled back and reinsulated the pin on the DFI module and it has been going sweet for 18months. cost me about 30c in connectors and silicone, and about 2 hours.

better than forking out 400 bucks for a new DFI module, or going to wreckers and getting one that could be near shagged anyway.

if the connection is good then yeah, probably up for a DFI. from memory there is a test for the DFI, but there is no test other than a SCAN tool for the CAS. both could possilby cause this condition, as could a problem in the immobiliser, that would produce a code though.