Astra ECU compatibility

[Aethir]

Hi everyone!
Sorry to be a partypooper by posting about Astras in my first thread...

Just have a couple of kinda-obvious but google-unfriendly queries regarding my innocent looking spawn of Shatner and the voodoo box that is my current woe.

Scenario:
My ECU started dying. And by dying I mean it's stuck in that happy place where apparently the timing is permanently dialed to 10°BTDC, and now my battery is dying because the ECU keeps turning the charging circuit off (hello, P0621). No power, at all, anywhere. Engine is unable to rev past ~2,200rpm; up to and beyond that speed the motor simply dies back down to around 1,300rpm. Being the ludacris bewildering piece of kit that it is, of course it blames every other component for its own brand of insanity... after replacing MAF and throttle body with no apparent effect in performance I started to really trawl the web for clues. Ended up finding a 2nd hand ECU; Repco ring me the next day to tell me something "wasn't right" and that I would need a) an ECU for a manual and b) would also now require a "security kit" for nebulous reasons that were never quite explained... after some hassle I managed to exchange the auto module for an immob/ignition/ECU set for a 5sp. Drop them into Repco. They ask vaguely about a CIM and then tell me they should be able to pair the original one.

$600 in labour, $450 in parts and 3 days later, I get my car back.
Exactly as I had given it to them. MAF/intake air temp errors and all.
And as a bonus, a P0335 error.

Took it to Holden dealer - by this time fuming - and after 90 mins of diagnosis they told me that the crank sensor circuit showed abnormal high resistance and that it would definitely have to be replaced. And that the MAF/intake faults didn't recur after an ECU reset. THEN they told me that the ECU itself had given them a P1600 - Internal ECU fault error. Changed CAS - and the ECU traded the 0335 for an 0621 (alternator circuit) error.

Question 1: if (as seems more probable by the day) it's an earth fault, what is the best way of tracking and eliminating it?

Question 2: what marks the difference between a ECU from an auto vs a manual? As far as I can tell the part numbers are identical, which implies to me that the difference between the two is programming and not a different pin out altogether.

Question 3: can similar but not identical ECUs be upgraded or overwritten? While digging for bitz this afternoon I came across a 5WK9451 (simtech 71.1). I need a 5WK9443 (simtech 71.6) - but my instincts tell me it can't be done...

Thanks heaps for being patient and reading all that!

[Gareth]

Im assuming its a TS Z18XE

The PCM's are he same, only the software is different from auto - manual, abs - non abs, etc...

the problem is you can only reset a PCM (or de-marry) before it is removed from the donor car, I don't know any wrecker who can do this. Hence why you have had to purchase a 'security set'. You need a TIS subscription and suitable pass through tool to be able to do this without a security set (not many shops have or even know about any of this).

Your fault still sounds like a faulty PCM, I have replace literally hundreds for similar reasons.

You paid repco to fix your car, they clearly didn't. Why did you take it else where? You paid for a service that they have failed to supply...

Hope that helps

[Aethir]

I wish it was a TS, I'd have had this fixed weeks ago... but noooo, I get the first of the AHs. The odd cousin with the Z18XE motor and a TS throttle body.

I know the CIM has to be divorced before removal, but have also had my Holden dealer tell me that their Tech2 unit can recode an ECU into the existing immobiliser system without prior resetting or having to fit a security kit - as long as I have the VIN from the donor car.

Selling it bundled in kit form is mainly so you don't have to have Tech2/TIS capabilities in order to swap an ECU successfully - at least that's how I understood it.

My issue being a faulty ECU/PCM is pretty much a foregone conclusion at present; my mission is to replace it as cheaply as possible because I've already dropped a bundle on it, I'm due to move interstate last week, and I'm rapidly running out of finance.

Repco, well... there's some dispute at present over whether the work instructions were to fit and code the parts to identify the fault, or to rectify it... at least if I take it to Holden they won't try to extort an extra $180 if the first programming attempt fails.

[Gareth]

I know the CIM has to be divorced before removal, but have also had my Holden dealer tell me that their Tech2 unit can recode an ECU into the existing immobiliser system without prior resetting or having to fit a security kit - as long as I have the VIN from the donor car.

The vin is stored in the PCM, and im calling BS on the rest of that.

The cheapest way out of this will be to get a security set from a matching donor and fit it yourself

[Aethir]

I do know where the VIN is stored, I also had a lengthy discussion about CIMs and ECU's with Holden mechanics, who were quite adamant that only the CIM *has* to be divorced from the donor prior to removal. They were also quite definite on their ability to recode an ECU independent of a security kit because I asked them specifically about it. This is a Holden service center, not a backyarder with a Chinese clone.

The entire reason for having that conversation with them was to confirm that if I was able to provide a matching # ECU independent of a security kit, that they would be able to install it successfully without my needing to buy another security kit... I can get a whole kit for around 2-250 but I'm just a bush mechanic who can strip a Landrover blindfold but dreads modern electrical work... probably end up having to do it anyway because we tore u-pull-it apart looking for one and the closest I got was the 5wk9451 from an 07/05 TS... another wrecker owes me an ECU (no kit) under a warranty claim (which is a drama all unto itself) but he's being a pain about stumping up. It's THAT solo ECU that triggered the whole conversation about recoding independently - because that would mean I pay $180 to get it recoded and be done in an hour, as opposed to 250ish and several hours for an entire kitswap.

Am not as green as I am cabbage-looking.

[Aethir]

Sorry for being a grouchy bastard... it's been a rough month.

I must admit, I've never seen such a diabolical recipe for failure as the expensive ones hidden away on a Z18XE... in 3 weeks I know more about its electromechanical ecosystem than I eeeeeever really wanted to know. Next happytime is the timing belt in about 20 thou... think I'll sell it before then.

What is the actual difference between a simtec 71.1 and a 71.6? Is it physical, ie different pinout layout, or different ICs, or is it purely software and programming? I'm intrigued now but googling just gets me a forest of ads for resellers...

[VX L67 Getrag]

The other option could be sending your ecu to logicar, they generally tell you if there's an issue before fixing it & can do most remanufacture work for around $250 & then no need to link or anything!

But then it's spending money with someone else & if I wasn't a mechanic I'd be taking it back to repco who you spent a bucket with for no fix!

[Aethir]

The other option could be sending your ecu to logicar

That was one of my first thoughts. Logicar alas told me that my particular ECU (the 5wk9443) is "unrepairable" and that they'd happily sell me a new one... I'm going to ring Injectronics tomorrow to confirm if it really is impossible to repair.

[HQ355]

Where are you located ?

[Aethir]

Western Adelaide.

You know, if any of you have a 5wk9443 laying about handy, desperate buyer known...

Is it at all possible/advisable to tap into the wiring harness at the ECU end and run my own earth to the relevant pins? Fault tracing a wiring harness is not my idea of a fun weekend, and time and money both are critical.