Hazards coming on after a bump or knock??

I have got me a 1996 300TDi ES and I have noticed an odd issue when off roading. It has happened twice now under the same circumstances. Basically if I hit a big bump or dip (bear in mind this is used mainly off roading) then the hazards start flashing. I have pulled out and disconnected the switch but they keep going, I have to take the under bonnet fuse out and they stop although I can still hear the relay clicking. I still have indicators however which is a bit odd, even after the fuse is taken out. After a few days (not sure exactly when but when I get back to it) its all OK again, doesnt run the battery down or nowt, just fixes itself...

I was wondering if the ES has some sort of collision detection crap or something in them? Or if anyone else has come across this problem?

Cheers

Yeah. It thinks its crashed. Mine does it too. resets after a while though

Not only the ES they all do, there's an inertia sensor that will unlock the doors (if locked) and activate the hazards, reset is by turning on/off the ignition switch. It dosen't fix it's self.

discool said:

Not only the ES they all do, there's an inertia sensor that will unlock the doors (if locked) and activate the hazards, reset is by turning on/off the ignition switch.

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Thats what I thought, mine doesnt reset though, not even after switching ignition off. Any ideas where the switch is? Can I remove it?

Jon

Under the glove compartment on passenger side. I think it is a green box. Check whether it is secure, if it isn't the slightest jolt will set it off. Unfortunately you cant just remove it as it is part of the alarm/central locking ecu.

Jongould said:

Thats what I thought, mine doesnt reset though, not even after switching ignition off. Any ideas where the switch is? Can I remove it?

Jon

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Its switch off and on again to reset, just off is no good.
Inertia sensor can go over sensitive if it happens on normal road bumps then u have a problem and the only way to rectify the problem is replace the alarm ecu.

My 98 tdi does the same thing and I have tried turning the ignition on and off but it still does it. I now drop the pannel under the steering wheel and pull a fuse out which stops it and I still have the indicators but if I put the fuse back in straight away the hazards start again so I leave it out for a few hours then put the fuse back in and then it is ok

discool said:

Its switch off and on again to reset, just off is no good.
Inertia sensor can go over sensitive if it happens on normal road bumps then u have a problem and the only way to rectify the problem is replace the alarm ecu.

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you mean to say there is no replacement for the inertia switch and you have to change the complete bloody alarme ECU ?? That's a lot of money on its way.... I think I'll use the "switch off and on" system

i used to just switch ignition on/off a couple of times when it happened to me and it reset

KNIGHTSPIDER said:

you mean to say there is no replacement for the inertia switch and you have to change the complete bloody alarme ECU ?? That's a lot of money on its way.... I think I'll use the "switch off and on" system

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It not a switch as such, it's a combinnation of electronic componants to make up a inertia sensor which would be suitable to only function in a crash and not with a parking bump etc.
But as componants do fail over time is why there is a fault and so the system is operating when it shouldn't, i'm sure u are just unfortunate to have a problem, although as mentioned in a post above make sure the alarm ecu is securely attached to the vehicle.

i only ever had mine do it when i hit it hard, normally on the sills

Cheers for all the replies, it is what I thought it would be so thats all good, its not going to be a problem as its only on big bumps (mostly when hill climbing and I land on the sills or guards). At least I know the reset procedure now, I will have to give it a go next time...

i had this issue and found the ecu loose so i packed it firm with some sponge and it seemed to sort it