Guys I am really not having fun anymore.

I just went to buy my used replacement "ecu" and not only are the numbers wore off---they tell me that alot of these "ecu's" have to be re-programmed by the dealer.

I have been talking to people here at club lexus for weeks now and not one person has mentioned to me that i have to re-program my "ecu".

My mechanic says that used ones dont always have to be reprogrammed.

I am shocked that no body here has mentioned this to me.

All they say is swap the old one for a new one.

Please let me know what to do guys!!!!!!!!

 

it may or may not, depending on the year of the car. I believe the following applies to OBD II vehicles, but im not sure if our cars are new enough for this.

when they say "reprogrammed" they probably mean to write the VIN code on the ECU so it matches with the car. If it doesn't match the check engine light will stay on all the time. It won't hinder performance, but the CEL is annoying. The only problem is that once a VIN code is written into the ECU, it CANNOT be over written with another VIN. The only way this can be overcome is with a new ECU, but they cost an arm and a leg.

If it's an older, OBDI car im pretty sure this does not have to be done.

 

hmmm, I've never heard of an ecu being needed to be reprogrammed to function properly. I have a 96 (obd II) with a different ecu and no problems at all.

I have a friend with a 2004 wrx with a different ecu and no problems there either.

As long as they're compatible (same year/or similiar year/same specs), you shouldn't have any problems. What StiCk3 stated might apply more towards bmw's and mercedez's but I'm not sure.

 

Thanks guys!!!!!!!

As always your advice is very much appreciated.

Ive been asking around and so far everyone says the same thing.

As long as the part is compatible it should be okay.

I figure with all the "ecu" swapping going on around here I would of heard more about programming them if it was necessary.

Thanks again!!!

 

The ECU will dump the RAM side when disconnected from power, only keeping the ROM side in memory.

The RAM side keeps all the info the sensors feed it. A lot of times people will unplug their MAF and battery and when they plug it back up an hour later everything runs like crap because it reset the RAM side where the sensor info was stored. Most of the time the car runs off the parameters already preset by the last sensor readings, BUT if disconected you better not have a bad MAF! It'll try to set new parameters off the bad maf and run like crap right out of the blue. You'll blame the ECU when you really have a bad MAF or Oxy.