: Gas Mileage Went UP after New ECM

05-13-07, 09:07 AM
A while back I posted a thread about the no-start issue I had with our 2004 SRX. The repairs took two weeks (one week waiting for GM to locate and ship the correct ECM) and consisted of a new ECM, Dash Interface Module, and ignition switch. Thank goodness is was under warranty.

Now for the pleasant surprise. Immediately afterwards, I noticed an improvement in gas mileage. I keep careful records of fuel consumption, and we compute MPG from gallons added at the pump, not the computer. Our suburban driving mileage has gone up from 16 to 18 MPG. Highway mileage has gone from 19 to 21 MPG. I have always been dissapointed in the mileage, until now. This is more like it. I attribute the change to different mapping in the new ECM. What else could it be? The other thing I have noticed its the vehicle fuel computer is much more accurate now. Mileage displayed is within 0.3 MPG of what I compute at the pump. Before, it was always optimistic.

If you have a 2004 SRX, please have a ECM failure so you can get the new one under warranty.

2004 SRX V6 AWD