I've having trouble re-programming a 99 355 to accept a new set of fobs. Below is a modified set of instructions originally written by Taz. Can anyone who has successfully re-programmed their alarm ECU please read my instructions and offer corrections. The new owner has tried multiple times to follow these instruction but has never got the LED to flash. He has been able to disarm the alarm using key strokes and the PIN so we know that's good My Instructions below: (not the real PIN) PIN = 3452 The car must be in immobilized condition, unlocked but with the LED flashing Insert the ignition key and wait 20 seconds with the ignition key in off. Turn the key from off to on and back to off as quickly as possible three times for the first PIN number 3. Count to 5 out loud (a good compromise between more than 2 and less than 20 seconds) before starting the second PIN number. Turn the key off-on-off four times for the second PIN number 4. Count to 5. Turn the key off-on-off five times for the third PIN number 5. Count to 5. Turn the key off-on-off two times for the fourth and last PIN number 2. Count to 5. Turn the key to on and the Alarm LED will come on and then go off. As soon as the LED goes off, turn the key from on to off and back to on in less than 2 seconds and wait for the light to go off. As soon as it goes out turn the key off then back on and wait for the light to go out again. Do this ten times each time waiting for the light to go off On the eleventh cycle the light will start flashing, now press and hold the new red fob until the light accelerates its flashing then release the red fob and do the same with the number 1 black fob, repeat with the number 2 black fob The Alarm ECU is now programmed to recognize all three remote alarm fobs and the fobs should be checked to ensure they are functioning properly.
The owner should not stop at the eleventh cycle but should continue to cycle the key until the LED flashes.
Thanks Eric, Are the rest of the instruction proper? particularly the part about waiting for the light to go out before starting the next cycle? "Do this ten times each time waiting for the light to go off"
