AFAIK if the X18 signal is missing it should still start? According to other posts etc the DFI only looks for the X3 signal to start. You can disconnect the PCM and the thing should still start on the DFI/X3 signals alone. I have not confirmed this!
Anyway, I went through the CAS woes a few months ago. It died once on a freeway. Engine lights etc but I didn't have the kit to verify the codes, and the paper clip method was too confusing. Add to that, if you Google VX Error codes, most of the results are for VT, which is entirely different.
It restarted ok that time. So I spent the time wisely going round to various mechanics to see if they would throw their analyser on it. I am amazed how many had no idea about the VX codes! One mob reckoned the camshaft and crankshaft had got out of synch and I needed a new engine (he was referring to a VE/VF I think). I took it to my gearbox guy who tried to read the codes, but the previous mob had cleared them. Good on ya!
It happened again, let me down but in a carpark. Bottle of water over the CAS and all good. Take it home. Plead with Envyous Customs to help me get my copy of AED working (again, after MANY years and PC rebuilds). Yep! They are great by the way!
AED diagnosed it as missing X3 and X18 pulses plus a few others left over from many years ago.
So I bought a Delphi CAS off ebay. Fitted it (very easy job once you know what you are doing). Lasted a few months... Got stuck on a weekend. So I went to Repco, bought another. Same brand as the ebay one. Fitted that. Then (I have said this in another thread), it was fine, until I got up it coming out of a roundabout. 40 k's, full throttle. Kicked down to 1st and off we went. Got to about 5000 rpm. Then stopped... No go at all. No engine light either. Wouldn't restart, so out with the water bottle. Sorted. Restarted, got home. Checked everything (missing X18 error codes BTW).
I could drive it fine, but get up it and it wouldn't like it. (Probably shouldn't be doing this at 331000 k's!)
So I bit the bullet and ordered a proper Holden one. Different brand than the ebay and Repco one, same numbers etc as on the original.
Fitted it ok. Went for a drive. All ok so far but I haven't got up it because it IS a bit rattly and I dont want the camshaft chain to give up at 5000RPM!
I try to buy the holden parts if I can. Spark plugs are the cheapest. I had a hose fail a while ago (at about 220000 k's) all original hoses BTW!
So I bought a set at SupaCheap (Aussie brand - well known). Replaced them all. One failed after a week! Back to Holden. Got the full set of all original hoses - part numbers etc stamped on them and all. AND the set was cheaper from Holden!
Ignition leads are way cheaper elsewhere. I got a set of Bosch from SC. Heat shields and all. But they aren't the same length as the proper ones. They are thicker so harder to fit, and no cylinder numbers. You get what you pay for.
How does this help the OP? If you buy aftermarket and the fault re-appears, it may be a faulty part you replaced.
