Reprogramming car key

[Tan]

Hi

I posted sometime ago that I was struggling to get my now late fathers W140 S280 to start.

One thing that was mentioned at the time was that immobiliser may be cutting in as the key may need reprogramming / synchronising with the car.

Can the key loose synchronisation and if so what needs to be done to rectify this?

The usual suspects of the battery in the key etc have been checked.

Thanks

Tan

 

[DSM10000]

The batteries in the key will have no effect, these are only for sending the signal for locking and unlocking.

What are the exact symptoms? does the starter motor turn the engine over?

 

[Auto-mobile]

point at the drivers door and press lock for 10 seconds then ignition on/off put the drivers window down when you do it so you can put the key in the ignition quicker, try a couple of times as you might not get it right. No harm in trying

 

[Dec]

What year is the car and does it have the earlier flip out remote key, below, or the later, all electric remote?

Dec

 

[Auto-mobile]

It will be das2 as above.

 

[Tan]

The car is 1998, it has the flip out key which controls the central locking and the alarm, there is not a separate alarm fob.

 

[Dec]

Did it pass the test above?
Do doors lock/unlock?
Does alarm arm/disarm, what lights flash when you lock/unlock?
What happens when you turn the key to start, does engine turn over, and do dash lights come on?
Is battery in good condition and both terminales tightly connected?

Check any fuses relating to central locking/infrared/alarm.

Dec