Have you tried the EKA ? (Emergency Key Access - negates the need for the alarm fob)
From 1996/97 300 Tdi Discovery Owners Manual
Locks and Alarm.
Engine Immobilisation Override (entering the emergency key access code)
If the handset is lost or fails to operate, the engine can be re-mobilised by using the key to enter a unique four digit emergency key access code. The code is recorded on the Security Information Card and is entered as follows:
IMPORTANT: ENSURE each key movement is carried out with care and precision and turned through the full extent of its travel.
After turning the key to either the lock or unlock positions, make sure it is FULLY returned to the centre (vertical) position.
If a digit is entered incorrectly, the WHOLE code can be cancelled by returning to operation ‘1’ and starting again.
1. Using the key. Turn the drivers door lock clockwise to the LOCK position and hold in this position for at least 5 seconds. Then return the key to the centre position. It is now possible to enter the separate numerical values of the four digits that make up the emergency key access code.
2. Enter the first digit of the code. If the first digit is 4, turn the key (anti-clockwise) to the UNLOCK position 4 times. Ensure the key is returned fully to the centre position after each turn of the key.
3. Enter the second digit of the code. If the second digit is 3, turn the key to the LOCK position 3 times. Remember the key must be fully returned to the centre position after each turn of the key.
4. Enter the third digit of the code. If the third digit is 2, turn the key to the UNLOCK position twice, ensuring that the key is fully returned to the centre position after each turn of the key.
5. Enter the Fourth digit of the code. If the fourth digit is 1 turn the key to the LOCK position once. Ensure the key is fully returned to the centre position after the key has been turned.
6. FINALLY, turn the key to the UNLOCK position once more to disarm the alarm and re-mobilise the engine. If the code has been entered successfully, the anti-theft alarm indicator light on the instrument panel will extinguish and the engine can be started.
If an incorrect code has been entered the sounder will bleep twice and the anti-theft alarm indicator light will continue to flash. In this case, return to ‘1’ and re-enter the code.
After three failed entry attempts, the security system invokes a delay period of thirty minutes during which the system will not accept any further attempts to enter a code.
NOTE: Once the engine immobiliser has been deactivated by entering the emergency key access code, it will remain inactive until a handset is used to lock the vehicle.
