Hey all- I remember reading here that if you disconnect the battery and remove the ECU, you will reset the car to factory specs or something like that!! can anyone share some info on the pros and cons of doing this. Also, of the 2 units in the box, which one is the correct one to remove?? I recently did a minor tune -up(plugs,wires,oil & filter, clay bar and waxing(he,he,he)) and want to document any differences in MPG, average speed etc. TIA, BD
(Oh, i checked the archives but too much stuff on ECU, but not my particular question) thanks.

Billy dee,

Yes, if you remove the ECU from the socket, you will reset the factory specs. It is not necessary to disconnect the battery before doing this if the car has been shut off for at least 15-20 minutes first. If you're concerend about removing the ECM without disconnecting the battery, you could alternatively just pull the fuse going to the ECM (check the box.. I can't remember the fuse #).

However, the reset to factor spec is only temporary. The next time (and every time) you start the car, the ECM will cycle through a "trip cycle" where it goes through a series of diagnostic tests. Some of these tests requrie that the engine be running for a significant period of time (up to about 30 minutes). After a trip cycle is completed, the ECM will begin adjusting various settings to achieve it's optimum settings based on the results it receives.

Hope this helps!

PS. - Beware of static electricity when removing the ECM! It doesn't like such things.... (Grin)

just disconnect the battery for about 5 minutes and this will clear all ECU codes and reset it.

you need the stereo code also to reset the stereo.

Dan