Engine Warning Light

[davidjt]

I recently had the immobiliser removed - all it ever did was flatten the battery. Now have the engine warning light on all the time, apart from the occasional flicker. Tickover has increased by about 500 revs. When attempting to read the code (using a paper-clip) the light flickers so much it's impossible to read: a simple wiring fault doesn't explain the increased revs, plus its a distraction and I'd rather it was functioning properly. Any suggestions gratefully received.

[RayD]

David,

Have you checked the base tickover

Ray

[ailwyn]

It suggests to me that removing the immobiliser has disturbed a sensor reading to the ecu, hence the light on and if the ecu is unable to establish the engine parameters then I could see this causing the engine to be "improperly" managed.

Suggest you try and find someone nearby with elanscan, or an alternative may be to video the paperclip flashes using a phone and upload it somewhere if you can't read the codes yourself.

It does seem really busy at first, but if you watch it for a bit and get used to it you should be able to pick out the codes.

iirc it flashes 12 12 12 <fault codes> 12 12 12 before repeating the same sequence.

[davidjt]

Thanks for that - I've never found my way to the Wiki before; before I invest in a computer lead (which I'll probably only use once) does anyone have one I can borrow for a couple of days? Cheeky, I know, but times are hard on a pension.

[davidjt]

OK - having established that the ecu wont talk to elanscan, it's over to plan B. I'm suspecting a vacuum pipe leak somewhere: is there a diagram (which I haven't found yet) showing all the plumbing on the engine?
Thanks

[HJ2]

David, before you established this... did you set the latency timer correct and did you install the cable driver correctly?

[davidjt]

As far as I can see, the set-up is all OK (comm port, latency etc.) All I get is the 'Bad Echo .....received C0 00' message, with an occasional 'no frame start byte received'. Given that the 'paper clip' method doesn't give a legible code either, I'm inclined to think that the genius who removed the immobiliser has screwed up some wiring in the process. There is one other possibility - a wire from one of the sensors right at the back (one with a black spiral protector) has been jammed next to a hot metal pipe and shows signs of charring - hence the need to establish which lead & pipe is which. The car is going to MSC tomorrow, 'may be needed for more than one day' and their labour charges are astronomical! Hence my attempts to give them a head start.
(Also, hoping the variable Everest chip won't put them off their stride - not sure how that factors into the equation.)

[HJ2]

I would lt the guy who c*cked up sort it and pay for it then!

[madbilly]

Sorry to get to this so late - my ElanScan does exactly the same but does actually record all the data. It could actually be missing things and me not know about it, but I don't think so. It may be worth having a go at recording a scan even if you are getting all those comms errors.

[CrtlAltSuppr]

Hello board,

With HJ2 help, I will make some tests on my alarm. But before doing this, here comes some thoughts.

When I have bought my car, the previous owner told me the alarm has been disactivated. Indeed, since the first day, central locking has never worked, and alarm key buttons haver never done anything.
Now that I have changed my battery, alarm is ON as you know, but the siren does not work, which could explain what the previous owner has done. However, I feel a little surprised that the alarm key has never worked, nore the central lock, so he has may be done a little bit more.

Is it possible that the alarm licro wave receiver and the central lock micro wave receiver are the same part? If yes, is it possible that the previous owner has simply disabled it?

[davidjt]

Latest mechanic has suggested that the ECM may be playing up - does anyone have a spare unit for an SE that they might be prepared to part with? Even just a short term loan would help us establish whether the fault is in the ECM itself or in one of the sensors.
Am I right in supposing that the parameters have been changed from the original Isuzu unit, and that ours are no longer available except from a breaker?
If all else fails, any electronic wizards camping overnight at Brands this year? The beer isn't great, but it's drinkable.

[ESM]

The symptoms are consistent with a bad ECU or an ECU power failure. The ECU might go into limp home mode for a sensor or PROM checksum failure but you should be able to read the code by the paperclip method, ElanScan or the garage diagnostic tool (I forget what they call it) if you can't get a code one way or another then the ECU may well be dead.

• There is an ECU fuse - check it before taking any heroic measures (Main fusebox - fuse 5 - 10A).
• Try to get the ECU to give you a code so that you know it's alive - use the paperclip method to avoid interface/PC configuration issues getting in the way. If you can get a code that way you can return to ElanScan with the confidence that the ECU is likely to be ready to respond
• If you can't get any response pull the plugs from the ECU and use a meter to make sure power is making it there. If the ECU power feed is patched through the alarm then it may still be responsible for your problem, even disabled, if it has stopped passing power through to the ECU for whatever reason

[davidjt]

Thanks for that; one of the puzzles is that having 'cured' the fast idle problem (I think they simply cleaned a valve and slowed the tick-over right down) the car drove normally, accelerating as it should, and felt OK. No restriction or evidence of 'get you home' mode. Now, suddenly, it's running too rich, but otherwise OK. (I've asked him to check the timing.)
And, of course, the CEL is still permanently on. It sounded from your post as though a bad ECM would simply be dead. Do they just expire, or can they fail by degrees?
David

[ESM]

In general the ECU is either alive or dead. Since it's running all right with the CEL on then the most likely thing is that you have an error detected but it's not one of those that kicks the car into limp home or applies the 4000rpm limit. Maybe a CO pot error since you have had an idle issue and a mixture problem? Try and read a code.

[davidjt]

Thanks again. I'll suggest that.
If the worst does come to the worst, I notice 'stevestrange007' has a couple of ECUs on e-Bay at the moment: has anyone dealt with this guy? Does the Sale of Goods Act apply to breakers?

[ESM]

I think the ECU is probably ok - if it was dead the engine would be tough to start, it wouldn't idle properly and it'd run like a bag of spanners. If you can get a code it should reveal the issue.

[davidjt]

The saga continues - I'm told that one culprit was a detached vacuum hose - don't know which one yet - but the car is running far too rich, cel still on permanently. Minimised with the CO pot, she would still fail an MOT. Current 'old school' mechanic is affordable (and trustworthy) but not on the internet. He has asked me to find out a) the expected voltage limits when adjusting the CO pot, b) the normal MAP sensor reading, and c) (in case it comes to that) what the fuel injection pressure should be. This may all be available on the WIKI, but it would save me a lengthy trawl through it if anyone knows the answers. Many thanks.
(Looking longingly at a midget-powered special - not particularly quick, but I seem to remember that (given the right tools) nothing on a BMC 'A' or 'B' series engine takes more than half a day to fix....... )

[ESM]

Going rich is often associated with a CTS or MAT sensor failure and they both set a code (and CEL) so if you want to go random replacement I'd start there (esp. CTS). I doubt messing about with the CO pot is going to do it - being rich doesn't set a code on the SE, the ECU has no way of knowing it's rich unless it has a lambda sensor and the SE doesn't. But I think you have to start with the ECU - the odds are that all your issues (rich running/CEL/no comms) are related. Something isn't right if you can't get codes. Usually a dead ECU gives a car that won't start but maybe, unusually, some element within it has failed or the power to it is intermittent or.....

I attached the diagnostic flow charts for No ALDL data / Won't flash code 12 (engine management pdf pp91-92) - I'd start there.

No ALDL data.JPG

No ALDL data2.JPG