starting after alternator exchange due to wrong connected battery

[Hanns Per]

On my "new" S3 from 2001 I changed the battery. Me idiot connected the brown cable from minus (on - I have a bigger black cable and the smaller brown cable) by great negligence to the + pole. Then I switched the battery master switch and realized very quick the smoke from the cable near the battery and somewhere out of the car near the engine. Realized my mistake and corrected.

Have no blinking light from the immobilizer now.

The lights horn etc. work, the starter turns the engine but I get no ignition. What could have gone wrong? I tried to read the wiring diagram without success. Thanks for advice

Hanns Per

 

 

[Jonathan Kay]

It's a bit hard to know where to start. How about:

1. Trace the positive voltage with a multimeter through the battery master switch connections.
2. Check the ECU fuse.
3. Inspect and wiggle all the earth leads and connections that you can find.
4. What's the voltage across the battery at rest and as you crank the engine?

Jonathan

[revilla]

Looking at the standard wiring diagram for the K Series, there is no protective fuse whatsoever in the supply for the immobiliser. It is wired directly across the battery, permanently live and unfused (in your case the positive feed will be taken off after the master switch rather than directly from the battery but the principle is still the same). I posted recently about the amount of wiring that is unprotected in this way. The same is true of the supply to the dashboard LED for the immobiliser.

What this does mean is that if the immobiliser is not working it won't be a fuse. It is worth disconnecting the supply for a little while and reconnecting as the immobiliser is microprocessor based and therefore can "crash" so a reset might just sort it (in your case this would just mean turning off the master switch for a while, so I guess you've probably done that already). I'm afraid though that the most likely scenario is that the immobiliser is irreparably damaged; the semiconductor circuitry in them doesn't really tolerate reverse supply voltage.

More worrying though is the fact that this is also the case for the main engine ECU. I know on the VVC version of this engine, reversing the battery polarity even briefly completely destroys the VVC control circuits in the ECU. It is quite likely to do other damage too. It's quite possible that the immobiliser and ECU are both fried.

When you operate the buttons on the key fob, is there any response at all from the immobiliser? Even without the LED you can usually hear relays within the unit clicking. Just thinking that there is a remote possibility that it's the LED itself that may have been damaged (they usually don't like a reverse voltage of more than about 5V).

When you first turn the ignition on (after it's been off for a few minutes at least) do you hear the fuel pump priming? And does then engine run for a couple of seconds and the die, or just not fire at all?

The best way to really diagnose the problem would be to swap the ECU and immobiliser as a pair with known good ones (they are coded together so you can't swap just one without getting them reprogrammed). I'm not sure what mapping and spec your engine would be, but standard K Series ECUs and immobilisers can be had very cheaply on eBay which would be good at least for diagnostic purposes. We can have a look which ones you have and try to find something suitable.

If you were local I would happily pop over for a look but I think Austria might be pushing it a bit!

Cheers,

Andrew

[phil 01]

When you consider the mass of the car is the return earth/neutral and we reverse that process we will possibly have cables with damaged insulation if it had to carry excess amperage, I think you need the scuttle off a do a visual because testing alone won't always show the fault, you could have lost insulation on a number of cables which further along could give you serious problems

phil

[phil 01]

Hello again if the immobiliser has burnt out Google Southern Car security for Sterling excel Immobiliser formerly Toad Powerkey £50.00 delivered.

[tbird]

"If you were local I would happily pop over for a look but I think Austria might be pushing it a bit! 

Hanns Per is an excellent host, lives in a beautiful area, you would enjoy the trip, and you could visit the Christmas market in Salzburg , a lot of plusses ,  Flights are cheapish   

 

Tim

[Hanns Per]

Hello thank You for Your extensive feedback. Does not look good though :-( !

I disconnected  and tried half an hour later, the light did not come up again, there was no fuel pump or relay sound when I turned the key. Only the starter turned the engine. There was no short firing up for a few seconds. I pressed all the buttons on the key short and long no reaction.

From your feedback I conclude ECU and immobilizer is damaged.

I am not concerned about the immobilizer which I would have taken out anyhow. Can I use a replacement ECU (1.6 K 145 hp) straight forward without immobilizer?

Rgds

Hanns Per

[simonpa]

Is you car EU2 or EU3?

Unless they have been unlocked (very unlikely), all the Rover K-series ECUs are matched with a dedicated immobiliser and it's matching plipper.

Buying a Rover ECU on eBay without matching immobiliser and plipper will just be a waste of money.

If you have a local Caterham (or Rover 200/400) owner with an EU2 engine, you can try swapping in their ECU and immobiliser and see if it works.  It should start and run (even if a bit rough.

Alternatively, thee may be a local with an Emerald ECU that you could try?

I have a matched SLR ECU/immobiliser/plippers that I could send to you to try - I'm not 100% sure it would work, as I bought it from another 7er on here, but haven't tested it...

Cheers - Simon

 

[revilla]

Yes agreed, the ECU and immobiliser are matched pairs.

You either need to replace the full matched set, or get them reprogrammed to match each other. Plenty of car alarm places can do that for you quite cheaply. I've got a T300 programmer myself at home that will do it (I've done several). Happy to do one for you for nothing but the distance makes it a little impractical.

The other alternative is to get an ECU reprogrammed to run without an immobiliser. You can't just unplug the immobiliser and expect it to work (wouldn't be much of security solution if you could!). The immobiliser actually exchanges a coded signal with the ECU to give permission to run and without it, it will shut down the engine.

If it's EU3, Mark Stacey at KMaps Tuning (used to be Z&F) will be able to turn off the immobiliser function in the ECU for you. He will even be able to provide you with an ECU with a nice tuned map for your specification by post at a price. He was one of the Longbridge engineers responsible for the original mapping and he has the keys to the back door! I don't think he can do much for an EU2 ECU though - if you are EU2 I think you would need to get a standard replacement EU2 ECU and just get it matched to an immobiliser and key fobs if they weren't already a matched set.

The reason I asked about the fuel pump priming and whether the engine starts for a couple of seconds is that (with EU3 at least) you would still expect these to happen even if the immobiliser was armed / disconnected / damaged which leads me to worry about the ECU itself. I think the ECU is designed to run the engine for a couple of seconds without immobiliser permission is because the handshake between the ECU and immobiliser uses a pretty slow protocol so if you just turn the key straight from "off" to "start" it doesn't have chance to sync with the immobiliser - so it starts anyway and then shuts down if it doesn't sync within a couple of seconds. This at least gives a pretty distinctive pattern of behaviour when the immobiliser is the culprit.

[SM25T]

Simon .... little chance of a local with a similar Seven !!

[tbird]

And to make things worse, I think the "new" S3 is may be his good ladies Christmas present ,  ooooops 

[Hanns Per]

thanks all yes its oooops, I literally "shot my baby down" but we do not drive during winter here, driving starts 1. April.

So I will take the immobilizer out of the loom (done this at my CSR) and get a MBE. Needs a new engine loom? or wiring the MBE plug. Anyone done this before?

thks Hanns Per

[sjmmarsh]

Hanns Per

I think that Darren on the CSR forum replaced the loom on his CSR, but there are bound to be others who have done it on a K-Series. 

Steve

[Hanns Per]

thks. did it in my CSR when changed fro mthe Ford ECU to MBE but I have no experience on the K engine. Will do some search

Hanns Per

[simonpa]

EU2 or EU3?

An Emerald ECU is plug compatible with EU2.

It's an easy conversion for EU3; Emerald can supply a new plug, connectors and wiring diagram with pinouts.  

It's also very easy to program and there are maps online (or from Emerald) for most K-seires configurations.

 

[Jonathan Kay]

Andrew:

I'm not labouring under any delusions about the knowledge gradient between us :-), but aren't there any simple things that Hanns should check first? Or does the silence of the immobiliser* exclude those already?

Thanks

Jonathan

* Or should I keep that pun in reserve for a future sensor problem?

[simonpa]

I'm pretty sure that even with the immobiliser disconnected, the fuel pump should initialise and the engine will run for a couple of seconds before the ECU tells the pump to stop.

The easiest first steps would be to try another ECU and see if the pump starts.
It would be a good idea to try replacing the fuel pump relay and fuse, just in case.  You can also try connecting the pump to a new live feed to check it will operate.

Next - check the ECU fuse(s) and finally, if smoke was seen and not from the ECU or relay, but from somewhere general, you may need to unwrap some of the loom to see if any wires have melted together.

Cheers - Simon

[Hanns Per]

So finally I got the engine running and the immobilizer unlocked. No light on the  immobilizer lamp. BUT when the engine was running the red light in the RPM meter turned on hence  the alternator was not working the car was running from the battery.

Today I put the new alternator in and now the immobilizer lamp is blinking and but  could not get this off by pressing the buttons on the remote control. Engine was running for a second and then shut off.

What is the procedure to get the immobilizer to turn off? Which button of the remote control do I have to press? How long?

Thank You for Your help

Hanns Per

[revilla]

If you disconnected the battery to do the alternator, the rolling code in the immobiliser and key fob may have gone out of sync. Press either of the button repeatedly until it responds to resync with the key. May need 8-10 presses I think. After that it should behave normally again.

[Hanns Per]

thank You so much should I do this with the key turned on (before starting mode)  or before touching the key at all? Sorry I am stupid on this.

thks Hanns Per

PS: there is another thing which strikes me, there is a purple black cable in the loom which goes from the relay nowhere it just as a female end in the loom. This cable does not show in the wiring diagram of the car and I cannot get the horn working, tested all cables and the horn, but it does not work with the button. Maybe this is related to the Immobilizer?? 

[SM25T]

Before you insert the key. Keep pressing the unlock button on the remote fob.

[revilla]

Yes just switch the ignition on then press repeatedly until it decides to respond again.

The only matching wire I can see on my wiring diagram is black with a purple stripe, which drives the fuel pump relay from the ECU. Where is this wire? Can you post a picture?

[SM25T]

Is it ignition on ..... or completely off .... I can't remember now !!

[Jonathan Kay]

PS: there is another thing which strikes me, there is a purple black cable in the loom which goes from the relay nowhere it just as a female end in the loom. This cable does not show in the wiring diagram of the car and I cannot get the horn working, tested all cables and the horn, but it does not work with the button.

Yes. I don't have a diagram with me but Purple/Black is conventionally "Horn or horn relay to horn push".

Jonathan

[Hanns Per]

Hello Jonathan thank You

in the wiring diagram and and in my installation  there is a purple yellow wire and a black wire connected to the horn button. When tested both have mass connection. The purple yellow wire goes to the horn relay. 

The purple black cable goes from tho horn relay and has no mass contact. however owhere in the wiring diagram I could find a purple black cable.

On the immobilizer I tried everything and experienced - slow red blinking - fast red blinking - permanent red - ECU relais clicking - and fuel pump running but shut off after starting and running for a moment.

What do I do wrong?

thanks again Hanns Per