The only place for a coil spring is up Zebedee's arse.
331 posts
Sep 02 2016
06 February 2017 - 19:04

Anyone had this problem ? The BONNET OPEN alert on the dash seems to be permanently on....

As many will know there is a micro-switch on the bonnet catch (- the adjacent to the battery -) which supplies a (local) earth back to the BECM (and on my pre-99 it is on Purple/White - Pin 14 - of C114)....

The bonnet catch earth does seem to get back to the BECM OK, but then it ignores it ! Might 'just' be the BECM playing up but any other ideas, chaps ?

On the positive side although the BONNET OPEN alert shows up I can still use EAS
(although I was previously under the impression that BONNET OPEN inhibited the EAS)

06 February 2017 - 19:30

EDIT: Yes, I know.... My brain is working properly again.... the switch is wired so it provides the earth when the bonnet is open !!!! Doh !!!

(I suspect the wire is just trapped somewhere...)

08 February 2017 - 18:32

Thanks for the advice chaps, much appreciated !

  • Sorted now based on cleaning/lubing BOTH catches and cables (as if you just lube the offside one there may not be enough tension on a single spring/catch to pull the Bonnet Release handle home). Whilst doing all this the 'permanent earth' problem disappeared and the main culprit seemed to be the wires on the microswitch (which were chaffed/cracked to bare wire just where they emerge from said switch). Resolved with a blob of epoxy resin and some tubing.
09 February 2017 - 08:06

And this ETM diagram might help explain my temporary stupidity - as far as the earth on Pin 14 (correctly) meaning that the bonnet is OPEN !

Convention dictates a cct. diagram usually shows the 'normal position' for a system, (ie. bonnet closed...) and that there is generally a 'failsafe' too - in that if the circuit is broken then that would indicate a 'risk' situation. Similarly if you pull the connector off there is nothing to tell you the bonnet is open..

Thus here it was interpreted by me as 'switch open' (ie. '0' on the diagram) means 'bonnet open' - Oopps - wrong !

enter image description here

09 February 2017 - 07:56

A photo might help explain what I said above about 'chaffed wires'; Red arrow shows the point !

Not sure how many operations it would take to wear through the wires.. Lots of bonnet openings would be needed.. as per any P38 ?!

Not my photo; My catches are metal: This picture shows (GR) Plastic variants:

-enter image description here

12 February 2017 - 08:16

Yes, that is probably how it is set up when manufactured; Still don't know why they later replaced the metal ones with (GR) Plastic though !
(Because of costs I expect, but are they better or worse ? Exposed situation so may be better in plastic, too ?)

enter image description here

09 February 2017 - 13:38

Well it gets riskier over time... and both my catches/cables were in need of lubrication and so could easily jam in the open position....
so then the real risk is if the bonnet subsequently wraps over your windshield at speed ! (Yes, unlikely - but not unknown...)

Seriously though it really is just 'good practice' to have a 'failsafe' indication... like many/most other cars do...

12 February 2017 - 08:25

Purists 'look away now' but what happens if you seal the NRVs in with silicone or (oh-oh !) epoxy resin ?

The problem with adding a customised (ie. non-OEM/pattern) block is that in theory you have 'modified' the suspension system,
which may be 'of interest' to your Insurance Company: Anyone knows what happens if/when you tell then you fitted coils ?

12 February 2017 - 08:05

A quick suggestion Morat - and at only £10 it will save each finger/toe from frostbite at only £1/digit !

enter image description here

12 February 2017 - 09:08

Thanks, a helpful tip! Guess you could tie-wrap it in on the plastic ones but I now will stick to (lubricated) metal !

13 February 2017 - 08:47

Yes, and I did some (necessary) research myself after my daft question and those are the ones; In context (Step 7):


Even if the o-rings are exactly the right size (and the 'right' material) in a well-worn block they will most likely leak.....(?)

17 February 2017 - 11:37

To be fair it will say 'FRONT INDICATOR BULB FAILURE' and the speeded-up click clack will indicated which side...
but perhaps the compromise here is to agree that the BeCM could be considered 'sophisticated' 20 years ago ?

On a more general point though I am quite serious that in these 'techy' days I do expect a car to tell me if there is
a problem - and just what that issue is (reasonably) specifically, not just (deliberately) flash up some "Check Engine"
light so I then have to go to the stealers to find out (and often at huge expense, of course) !

If it were not for BBS 'cracking their secret code' I really wonder many P38's would still exist ?

21 February 2017 - 07:23

Apologies, Gordon; Probably my fault as I did not explain my ‘Doctor/Disease’ comment well - but it was just intended as a criticism of the other site. Time was this had a flourishing ‘Diagnostics’ section of course, with regular/excellent contributions from Storey Wilson and Colin from BBS etc. The latter also offered a discount to members (but Toad/Carl scuppered all that due to the ‘disease’ - self-interest.- once he ‘misappropriated’ some P38 test equipment). I was actually a little surprised that this has now apparently spread to Doctor/Scotty.

All we want to do is keep our rigs on the road of course…… and if I do manage to get some BeCM Information from LR this will go straight to the real gent here, Marty !

15 February 2017 - 17:02

I think we all know there are lots of doubtful Chinese parts on the interweb now but I just spotted a 'new' trend. (New to me anyway)

Not actually a P38 part but I bought something on ebay listed as OEM..... but when it arrived it was labelled as Original Engine Management !!

So beware.. OEM may just mean 'Old Elephant Muck' now....

Any other similar/blatant examples to report chaps ?

16 February 2017 - 11:53

Maybe I am being too picky but if it told me exactly which bulb was gone (and the type of bulb) I might be impressed......
Unfortunately the BeCM remains 'State Of The Ark' to me !

EDIT: Come to think of it I also want it to provide me with Fault Codes without an external box....
even if that meant JLR could not charge me an arm/leg to read/reset them,,
as per their original intention !

17 February 2017 - 17:13

Ferryman wrote:

Oh well, I thought I'd say something nice about the P38...

Ah, Ok, that's a different matter... Mechanically it is really solid; Electronically though it is like blancmange - or do I mean merigue...!?

Anyway I am sure that we all have our stories about our P38s but quite a few years back I was very impressed when I (accidentally) drove through 3' of water at speed (- thought it was a wet road not a flooded one....); About 20 yards of it - but the car hardly twitched.. excellent...!!

Somewhat later I realised just what would have happened if I had stopped in that 'stream' and the BeCM got wet !!

Oh and my other half will not even drive it - thanks to (too) many 'Key Code Lockout' episodes...

18 February 2017 - 11:17

Interesting discussion.... but again I would suspect the usual 'Reverse Engineering' problem here: Not just getting the Code off the chips but interpreting it accurately enough to modify it (?). Serious point though - is it worth us asking LR as a 'group of enthusiasts' etc for some (really) useful 'secret' BeCM info ? If their T4 is no longer about it would seem like a very reasonable request....

18 February 2017 - 12:09

Hmmm... sounds less like a Doctor and more like a Disease then ?

That's appalling, sorry to hear that Marty: Looks like a BeCM guru like you can get a good handle on the hardware/contents but it could still stall for firm/software reasons unfortunately

I will (try to !) open a dialogue with LR anyway and report back; A while back (when I was trying to develop a cheap SRS-resetting tool) I had a dialogue with some non-LR folks who indicated that LR sometimes sell proprietary protocol etc data to third parties. Obviously this is not much use if LR ask for £££ for BeCM secrets etc but as they have not made these for 15 years maybe they will be more 'understanding' now (but don't hold your breaths !)

17 February 2017 - 19:02

Well I certainly have to agree with your comments about French/Italian reliability; Many look great but some don't even qualify as 'cars' IMHO !

But, being more serious for a moment, it's not just about blown bulbs (which frankly we should notice anyway... eg. in the dark..) but I would only really consider the BeCM 'sophisticated' if it could be re-programmed to do something different and useful (if necessary) - and top of the list would be an (audible) engine temperature alarm, followed by a CKP failure indicator (although I realise the ECU would have to send that info. to the BeCM) ! ( Plus a few other driver-friendly things,,,)

There is really no reason why a truly sophisticated system could not for instance display more useful data than 'EAS Fault' and 'SRS Fault' /'Airbag fault' and the like... As I said earlier I know this is not meant to help the owner, it is intended to help the stealers..... Obviously (slightly) later full OBD compliance and CANBUS etc are certainly better and much more sophisticated.

Maybe I am too aware of (US) OBD developments but LR however clearly chose to keep the data available to owners to a minimum: There is enough intelligence in the BeCM to do more.. but it's 'a secret'. And we won't 'Save The Planet' by buying new cars just because our old ones have (££) 'secret systems'. After 10 years the manufacturers should make the code freely available/ /Rant Off - but better stop anyway before I start to talk about diesels/evils !!

23 February 2017 - 17:05

Sorry yes I realised that - I meant the Driver Pack connections inside the EAS box itself.....

The problem may not just be the pins - it can be weak/bad crimps too.... and the problem can be exacerbated by frequent manipulation of the M/F plugs