Mercury Grand Marquis 2004 ECU

tiopirata

I have installed a new ECU from a reputable supplier in my Mercury Grand Marquis 2004. The dash goes blank when key is turned to start. Car would staret half an hour previously with old ECU, battery is new. Any ideas?

tjc78

I’m thinking most likely the key (anti-theft) has to be re-coded to the car. Information on how to do it should be available with a quick Google. I’m not 100% sure but with a new computer this may require a dealer visit.

tiopirata

I am in Panama so no dealer. I shall wait to hear from the seller of course but I thank you for your advice.

tjc78

OK, some dealers that sell new ECUs offer pre-programmed keys. Without a dealer, this may be your only choice.

Sometimes larger locksmiths have the equipment to program the keys as well.

tiopirata

Thank you, will check this out. I have never had electronic keys or fobs for this vehicle so hoping it may not be an issue.