Hi,
I have been offered a Rover 418SD on an "M" plate cheaply, by a mate who owns a service type garage.
The car has no remote controls - and has apparently not had for some time - and the immobiliser has activated. He has the key-code (left-right-left-right-left), though that doesn't have any effect.
He said that he could get the immobiliser guys out from a few miles away to disable the unit, at a cost of £50, or I could have a go at it myself (I do various electro/mechanical fault finding/repairs for a living, though not electronics).
I said that for the money he may as well get the guys out to do their work, so he called them. They said to him that there are three wires going to the door lock, all he needed to do was to connect two of them together, that would result in the immobiliser being permanently disabled.
I said that I would have a look at it, which I did this morning. The back of the tumbler assembly has a microswitch attached, which can be heard to make/break as the lock is turned. However, there are only two wires to the switch, one at 11.5v (battery 12.5v plus) relative to chassis, the other at 0V, shorting them had no noticeable effect, on removal of the short, one wire returned to 11.5v.
The fact that there are only two wires to this switch indicate to me that the central locking expects only one signal for lock/unlock, and upon receipt of the signal, merely changes state, ie if locked it unlocks, and vice versa. Which leads to the conclusion that the "left-right-left-right-left" immobiliser code key input relys on the central locking actuators to generate the codes back to the controller.
But on this car, the central locking isn't working either... And the above scenario cannot be right either, otherwise repeated left turning of the key would result in lock - unlock - lock etc. which isn't the case.
So the locking mechanism (5 wires) must have an input also... Makes your head spin, especially at this time of day, with a bit of lube :-).
Anyone any ideas? I guess that the first thing to do is to get the central locking working, all the fuses are ok, I understand that there is a module under the driver's seat, though haven't checked it yet. If deemed more sensible, I can be emailed at
snipped-for-privacy@ntlworld.com