Hondo

I took my truck in today to have two codes checked. Battery temp sensor and Low speed fan relay. No parts in stock but ordered to be replaced under warranty, no BS no question just done.

Then I had them reset the computer to the new tire size. I only went up from 265/70/17 to 305/70/17 only about 2 inches difference if that in diameter. Well to make a slightly long story longer... They only charged me $25 to reset the comp so I didn't even look at the bill.

I got in the truck and started out. It felt very responsive. I got on the expressway home and the truck just seemed to run up to 80 effortlessly and at very low RPM (I have not been able to check the mileage and speed with GPS or mile markers yet) Also the overhead computer which had been showing mileage of 12 MPG's or so since I put the bigger tires on was now showing 19 MPG.

When I got home I looked at the bill and this is what it read

Reset ABS Controller to New Tire Size
Replace Engine Distributor Control Module
Reset Values to Tires


I didn't even question what they did as I have to go back next week for the other parts so I will ask then but does anyone think that the EDCM is just another way of saying the ECM? It seemed to take a long time to do just the tire recalibration and I couldn't watch but WOW it just runs so much nicer and effortlessly. Could there have been a problem that wasn't shown on the codes I could see?

My old dealer would have tried to BS me into having to pay for something or would have told me nothing was wrong.

Sorry to be so long winded but after a pretty week at work and a lot of stress I am pumped to be treated so well with no fuss and BS and have a highly noticeable improvement in my truck to boot.

Any ideas?


Thanks

Hondo

AaronT

I think they just threw in the EDCM for diesel instead of ECM. Just my guess as there is no listing for EDCM in the service manual.

gatf4

Sounds like they did a reflash on the computer to me.

Hondo

Well the bill said

REPLACE Engine Distributor (not diesel) Control Module. I wonder if they found a problem with the old one or if they fried it doing the Flash for the tires. Guess that I'll have to ask when I go back for the other work... but then again maybe I don't want to know as it is running great!

Hondo

bigblock2stroke

I doubt they would just replace the ECM. Very expensive and also must be approved by STAR center. They probably reflashed it though.

The letter D is right between E and C on the keyboard, it was a typo. Either that or they put in a new distributor (haha). Prolly changed the plugs and ignition wires too.

I am also a proponent of larger tires to reduce the numerical final drive ratio and bring the rpm's down at cruising speed to increase fuel economy. Some here don't think it works.

Hondo

Well all happiness aside I went out on the Thruway today with my GPS and my calculator and they went too far with recalibrating my Speedo I am picking up an extra half mile for every ten and I am showing about 4 MPH faster than I am actually going which will make my warranty run out faster. After I put the tires on I was only going about 2-3 MPH faster than the speedo said and I was getting time on the warranty so I am actually worse off but the truck does seem to be running much better.

Hondo

bigblock2stroke

Your speed is always set on the + side (reads faster than actual) because they don't want you trying to get your speeding ticket paid for because the speedo only said you were doing X and you were actually doing X+4. I haven't had them be more than 4mph off, usually they are about 2 mph off. You'd be surprised how air pressure can effect your "revs/mile" too. Also, there is some "slop" in the calculation due to the fact that the tire "grows" the faster you spin it.

Check the tire manufacturers listed "revs/mile" and make sure that is what the dealer put in the ABS module.