Inside immobiliser

Inside immobiliser

Author
Discussion

ianwayne

Original Poster:

6,292 posts

268 months

Friday 14th October 2016
quotequote all
Thought others may be interested.

Recently, I've been having to squeeze the immobiliser M36T2 in my Chimaera to get the fuel circuits to enable! That, or turn the key on and off a few times until I hear the fuel pump run.

Replaced it with a unit from Abacus alarms. Plugs in, sorted. The only downside is that I have to disable the immobiliser with the touchkeys provided every time, because it isn't synchronised with the M99 alarm. I can live with this.

Anyway, since it was knackered, I broke into the old one. Drilling the locating lugs out and prising it apart reveals this:



There is a heatsink inside and all the relays are potted in heavy duty rubber:



This is as far as I went. Interesting that it is marked as made by Siemens in Portugal.

Now in the bin, but it shows that these are not really repairable.

Sardonicus

18,960 posts

221 months

Friday 14th October 2016
quotequote all
Many modular alarms with separate circuit break/immobilizers modules are constructed like this wink

taylormj4

1,563 posts

266 months

Saturday 15th October 2016
quotequote all
Good one. I've been thinking about doing this on mine to see if the relay was replaceable.
I'll not bother now !

Cheers.

kennybgr8

379 posts

142 months

Sunday 16th October 2016
quotequote all
Am I right in saying the immobiliser is under the dash or cent console 🤔

ianwayne

Original Poster:

6,292 posts

268 months

Sunday 16th October 2016
quotequote all
It could be in either place. My immobiliser was behind the stereo. The cable to the loom is very long though, so I actually had it routed to be hanging out of the passenger side cubby pouch aperture while I was fault finding.

The left hand bolts aren't too bad to get to so I've put the replacement up under the dash top. Neatly of course. yes

Polly Grigora

11,209 posts

109 months

Wednesday 25th October 2023
quotequote all
If it was possible to replace the relays within an immobiliser the immobiliser wouldn't be up to being classed as an immobiliser

Thief proof to a good degree is what it is, circuits within the box of tricks must be protected, car thieves don't have enough time to chip away at potting compound, they can't cope with belling out black wires to work out what connects where

Potting has prevented many thefts in the same way as black wires have