Jayalpert

I need to replace the ECM in an 02 SC430 my question is.......?

If i get my hands on a used one will I still have to Reflash the ECM or will the car start run and drive plug and play??????

sc430faste

pretty sure you have to flash it since our keys have chips in them ...

LexBrett

Think there is a method on CL that shows step by step how to link the ignition key to a newly installed ecu.

Just curious, why do you need a a new ecu? What happened? I ask because I have an erratic idle problem, and believe it could be a bad ecu? How exactly did you determine the ecu was bad? Where you getting reading on your obd2 reader? Did you buy an ecu on eBay??

sc430faste

Quote from our GS430/gs300 buddies, the ecu is programmed to a master key, if you get a new ECU, make sure you get a new master key, you cannot reprogram an ecu for your existing keys


http://us.lexusownersclub.com/forums...u-on-98-gs400/

LexBrett

Thanks for the response!! I think what we are trying to figure out is whether the new ecu needs to be reprogrammed by the dealer. If getting a master key, and programming the ignition, is all that is needed for DIY that is doable. BUT if taking to stealership is required, I give up! Thoughts anyone??

Jayalpert

I was actually wrong it turned out i was dealing with a bunch of sub fuses that had blown due to a customer reversing the polarity on the battery. In response to your problem. Is it only at idle that your rpm is irradic?

LexBrett

When I start the car the engine turns over. Then barely stays on, with crazy misfire, random misfire code as well as misfire in each cylinder. Throttle moves on its own at times and revs. After a few minutes it calms down but still misfires. Depress the throttle and sometimes get a response sometimes do not.

My next step is to switch out the Throttle Position Sensor, at least if it is not the TPS I can rule it out... thoughts??