Hi, my N REG 406 diesel was working fine, i fitted a stereo and replaced some fuses that were missing (now removed) and now the car asks for the keycode to start (where it previously didn't). I've been told by the previous owner the code is 1982, but the keypad denys it. Any idea's how to get past this? Is there a service/ workshop code to get the thing running again? thanks. james
406 Immobiliser problem
Jan 05, 2005
1 Replies
If the keypad has a 68HC motorola MCU inside then this can be dumped and the code read from there. You will need specific hardware and software to be able to do this.
By far the easiest way is to read the 93C46/56 eeprom inside the ECU, there are a few ECU's which have a micro, however most have eeproms. Simply read the data from the chip with any compatible reader/programmer.
When you look through the dump you will see the code repeatead several times (but reversed), for example:
0143 0143 0143 0143 is: 4301 1234 1234 1234 1234 is: 3412 and so on.A new/virginised keypad will be supplied by your dealer. There aint no way they'd even attempt any of the above!
Hope this helps.
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