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)

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...)

Unplug the switch first. Could just be a jammed/ shorted switch.

I had this issue a couple weeks ago. Intermittent on certain bumps. I removed the latch and bent the metal tab towards the micro switch. No issue since.

I tried to bend the tab on mine and it snapped off.... I just unplugged the microswitch so the BeCM thinks my bonnet is shut even when it isn't. Not ideal from a safety point of view but it stopped the message on the dash.

Just to be different mine was actually down to a sticking cable/latch setting off the alert. I just re lubricated it all. It never inhibited my EAS either.

Eas will still work with bonnet open,, tailgate and doors are the inhibitor . When I close my bonnet, unless I put direct pressure on the catch I get the message, slam it and it's ok.

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.

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:

-

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 !

Oh well, how risky is the situation when the connector is pulled and you don't get the message?
This is my first car (I've had a few) with such a feature and yes in the past it has happened that I drove off with a bonnet rattling in the safety-catch. I survived.

Not very I would say. You've got two catches (and only one has the switch on it), then there's also the safety catch and a very heavy bonnet. It isn't like some modern cars where the bonnet is so lightweight a gust of wind will flip it up over the windscreen.

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...

Agree totally, plus if it's fitted it should work.

So right. When I got mine it took pretty much force to open the bonnet, it felt like the handle almost broke to open it. As I did not wanted to break a cable I adjusted the catches in a way that the bonnet locks when you let the bonnet drop by itself say the last 25 cm. In locked position it just presses in the rubber by a few millimeters and the switch is actuated.
Tony.

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 ?)

If my experience of the plastic ones is anything to go by, the slot where the cable outer engages wears and the outers can slip out. The metal ones obviously won't have that problem. My vote would go with the metal.

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

Which is exactly what I did!

davew wrote:

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

davew wrote:

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

That's what I did, drilled two little holes where the outercable runs underneath and tie-wrapped it up so the outercable cannot fall outof the slot. (did it both sides)