2003 Saturn LW300 ECM


Asked by Jun 24, 2016 at 05:56 PM about the 2003 Saturn L300 Base

Question type: Maintenance & Repair

Changed the motor in my car. I put my original ECM on the new motor due to
the one that was on it wouldn't start my car. When I put the ECM on it from my
original motor, she will start and run cold, after heated up and shut off it'll start
but when you push the gas there's a hesitation and the rev takes a few seconds
to increase but will only go half rev......any suggestions. I've checked all
connections, fuel pressure, exhaust, everything except flash the ECM. Is that
what I need to do?

3 Answers


Forget flashing the computer, unless you have the electronic gear, and what would you flash it too? The correct PCM is the one designed for the engine, fuel map and timing map, If you changed to different year engine it might have a series change? I don't know Saturns base,should be a 2.2 liter? but engine management is all the same, Next is the vehicle harness and cluster mileage and PCM are all coded together.. So buy the correct PCM for the year engine you installed and change the rest of the car so it runs with the factory engineered fuel and ignition timing and all maps


Actually it's a 3.0L V6 24 cylinder twin cam.


That's a big job is it not to change all the wiring harness in the car??

Your Answer

Add photo

Related Questions


Looking for a Used L300 in your area?

CarGurus has 122 nationwide L300 listings starting at $2,500.


Search Saturn L300 Questions

Saturn L300 Experts

#1 Tom Demyan
Tom Demyan
Reputation 430
#2 dandyoun
Reputation 240
#3 tenspeed
Reputation 100
View All

Related Models For Sale

Used Saturn S-Series"
1,138 listings
Used Saturn ION"
5 Great Deals out of 1,638 listings starting at $1,983
Used Nissan Altima"
1,404 Great Deals out of 87,430 listings starting at $1,195
Used Saturn VUE"
62 Great Deals out of 2,828 listings starting at $1,000
Used Jaguar S-TYPE"
29 Great Deals out of 610 listings starting at $1,000
Used Buick Regal"
182 Great Deals out of 10,510 listings starting at $1,995
Used Mazda MAZDA6"
238 Great Deals out of 15,126 listings starting at $1,495
Used Volkswagen Beetle"
254 Great Deals out of 9,185 listings starting at $1,400

Used Cars For Sale

2004 Saturn L300 For Sale
96 listings starting at $2,500