05 to 03 ecm flash
- Thread starter rebel127
- Start date
joefarmer
MR. Supreme Overlord
Really? I show the ECT sensor is in a different hole on the C1 ECM connector for 03 than 04's. I wouldn't mind confirming this isn't the case.
Scooter's Roofing
New member
yup, if you put an 03 ECM in an 04, the temp gauge will peg out. but flashing an 03 ECM into an 04 calibration won't damage it and aparently will work fine.
Scooter's Roofing
New member
if you put an 03 auto ECM in an 04 auto, the temp gauge will peg out and the gear indicator won't indicate in 1, 2, D, only PRN, and the tranny will limp. The 03's have an external PCM. I guess they figured out how to integrate the PCM functions inside the ECM on the 04's.
joefarmer
MR. Supreme Overlord
Someone sent them to me, but they have to remain private for the time being.
I am currently looking into upgrading my 03 manual ECM to an 06. Would this be possible if the harness and ECM where upgraded to an 06? I understand the differences between the buses but am curious if the harness was also upgraded if it would work. How will this effect the CAM sensors ect.. ?
Last edited:
Scooter's Roofing
New member
injectors are the same... the injector HARNESS is different... hence the need for an 06 harness to go with the ECM
seriousdiesel
New member
Did it play well with the gauges in the dash and rest of the truck wiring?
Not asking if the HARNESS needs to be upgraded. Asking if any sensors will also need to be upgraded to 06'
Scooter's Roofing
New member
Thank you IdahoRob. thats what i was looking for.
duck_04
resident quack
I wasnt able to get it to work. Whats the secret? I took an ECM out of an 03 auto, put it on an 04 auto and ran a recovery file VIN specific to the 04 on it. It took the file fine, and the truck started and ran fine, took fuel fine and all the gauges worked. When the truck was put in gear, the TC would lock and kill the truck. I know on the 03's the PCM is external, and in 04 the PCM functions are integrated in the ECM.