Ecu tuning 2002/2003 g35sedan (very technical)
Felt like this post belonged in this thread:
Swapped my new engine in out of an 08 m35x with 22k miles (swapped upper oil pan to convert to RWD)
Performed 04.5 upgrade on my early 04 for all the latest goodies, what it took:
04.5 engine harness
04.5 and up newer ecu (uprev flashed with nats disabled to remove IPDM/bcm dependencies)
04.5 proper dash harness (non bose/non navigation)
oem wideband sensors for the manifolds
04.5 transmission and valvebody with transgo installed.
I'm now data logging with the integrated wideband support and etc..shifts like a bat out of hell
Swapped my new engine in out of an 08 m35x with 22k miles (swapped upper oil pan to convert to RWD)
Performed 04.5 upgrade on my early 04 for all the latest goodies, what it took:
04.5 engine harness
04.5 and up newer ecu (uprev flashed with nats disabled to remove IPDM/bcm dependencies)
04.5 proper dash harness (non bose/non navigation)
oem wideband sensors for the manifolds
04.5 transmission and valvebody with transgo installed.
I'm now data logging with the integrated wideband support and etc..shifts like a bat out of hell
Last edited by JaE35; Dec 19, 2013 at 10:22 AM.
It still uses the DE
Joined: Jan 2007
Posts: 1,311
Likes: 73
From: Miami, FL
JA,
I was actually looking into doing this. So you had to change the transmission?
How about the electronics ... did you need the console for the radio or ac buttons?
Dash/Speedo?
What other details of you have any can you spare? I gave up on osirus and every other method I much rather upgrade the ecu and wiring if it can work.
When you say nats what do you mean? I know there's a bunch of digital signals in our cars... how hard was the work needed to be performed other than swapping things out?
I was actually looking into doing this. So you had to change the transmission?
How about the electronics ... did you need the console for the radio or ac buttons?
Dash/Speedo?
What other details of you have any can you spare? I gave up on osirus and every other method I much rather upgrade the ecu and wiring if it can work.
When you say nats what do you mean? I know there's a bunch of digital signals in our cars... how hard was the work needed to be performed other than swapping things out?
JA,
I was actually looking into doing this. So you had to change the transmission?
Yea, mine was at 180k miles and the time had come. I do however suspect you can get away with just swapping the valvebody if you have an earlier model. You essentially delete the separate TCM in the kick panel.
How about the electronics ... did you need the console for the radio or ac buttons?
Put about 13 hours reading the FSM and all of the wires match up perfectly. There are a couple of extras in the ignition signal system and how they communicate with the BCM which is why I had to swap the dash harness. With just the new engine harness and my old dash harness it would not talk to the BCM to ECU.
Dash/Speedo?
All dash functions are 110%
What other details of you have any can you spare? I gave up on osirus and every other method I much rather upgrade the ecu and wiring if it can work.
I spent a ton of money on this install and sold a lot of mods I wish I could've kept to support it. It's very worth it if you can source a donor. I'm enjoying the upgraded transmission computer.
When you say nats what do you mean? I know there's a bunch of digital signals in our cars... how hard was the work needed to be performed other than swapping things out?
The vehicle security system, obviously when you swap an ecu it has to be programmed to the key to activate everything else for the ignition features to run their course..(start up fuel pump and etc) I overrode that to save a few bucks since the ecu was already uprev tuned.
I was actually looking into doing this. So you had to change the transmission?
Yea, mine was at 180k miles and the time had come. I do however suspect you can get away with just swapping the valvebody if you have an earlier model. You essentially delete the separate TCM in the kick panel.
How about the electronics ... did you need the console for the radio or ac buttons?
Put about 13 hours reading the FSM and all of the wires match up perfectly. There are a couple of extras in the ignition signal system and how they communicate with the BCM which is why I had to swap the dash harness. With just the new engine harness and my old dash harness it would not talk to the BCM to ECU.
Dash/Speedo?
All dash functions are 110%
What other details of you have any can you spare? I gave up on osirus and every other method I much rather upgrade the ecu and wiring if it can work.
I spent a ton of money on this install and sold a lot of mods I wish I could've kept to support it. It's very worth it if you can source a donor. I'm enjoying the upgraded transmission computer.
When you say nats what do you mean? I know there's a bunch of digital signals in our cars... how hard was the work needed to be performed other than swapping things out?
The vehicle security system, obviously when you swap an ecu it has to be programmed to the key to activate everything else for the ignition features to run their course..(start up fuel pump and etc) I overrode that to save a few bucks since the ecu was already uprev tuned.
I drove an 05 and the most striking thing to me was how much better the shifting was. And that was just stock-to-stock.
So I assume an 04.5+ Transmission wouldn't work with an 03.0 ECU eh?
So I assume an 04.5+ Transmission wouldn't work with an 03.0 ECU eh?
yeah, the biggest problem with this for the early 2003 guys is that the ECU is not interchangeable - so its not just a wiring harness and TCM/Valve Body swap - you essentially have to replace the entire car 
as for just changing out the VB - i think the wires/connectors might be different at the transmission and therefore you would need to swap entire trans
as for just changing out the VB - i think the wires/connectors might be different at the transmission and therefore you would need to swap entire trans
Registered User
Joined: Jun 2010
Posts: 34
Likes: 2
From: NE IL
Ya buddy. Uprev has had my ecu since last week. I lost it while flashing and they are recovering/testing. Hopefully when I get it back it is tuned....lol. I am under a foot of snow here so not driving my car anyhow- and told them to take their time. I have some ART pipes to install but not even sure if I want to without a tune.... I will let ya know ASAP when I know more!!
Im planning on getting a salvage 6MT soon and will be swapping the transmission and ECU into my car. Does anyone know just how much of the wiring harnesses will I have to swap to make it work?
Registered User
Joined: Jun 2010
Posts: 34
Likes: 2
From: NE IL
Sorry I haven't replied sooner all. I started a new job in April and things have been hectic. Unfortunately Tollbooth was right. After all was said and done my ecu was fried, and UpRev gave up and got me a replacement and a refund. I installed ART pipes in anticipation of a tune and now am stuck with a car running super rich and bogged down. It sucks. What other options do I have for tuning?
