LQ4 Throttle By Wire conversion
 

Hello everyone.

I have searched for hours on the net but everywhere i go it seems forums dance all over the FBW (fly by wire) to cable throttle body converson.

1) What years 1500 - 2500 6.0 LQ4s came with a cable throttle body?

2) What is needed to convert from FBW to cable throttle?


I have heard alot of different claims of certain year LQ4s having more or less HP than other years?
Any help would be greatly appreciated.

I believe it was 2003 when the LQ4 converted over in the HD trucks. But I think some tahoes and suburbans had DBW prior to 2003. My 02 escalade engine shared the same DBW unit as the Corvette (which is not the same as the 03+ DBW unit). As far as converting, you need the wire harness and the gas pedal. The throttle body will bolt right onto the intake.

Regarding different power ratings, it's mainly due to the fact that the engines are rated at different RPMs. For example, the LQ4 in HD trucks is rated at 4400 rpm whereas the denali and escalade engines are rated at 5200. There is no internal difference between an LQ4 rated at 300 and one rated at 335

Thank you for that information it was very helpful. I do have one or 2 more though.

1) I will be cutting the wiring harness down and having the computer re-programed at the same time. Will i be able to bolt on a cable throttle body, cut that circuit out of the harness and have the computer programed to comply?

2) What vehicle would i need to steal a TB off of? Will a 4.8, 5.3, etc work?

1. shouldnt be too much of a problem, as long as the pcm still "sees" TPS, throttle blade and ICU function.
2. Any 78mm will do, they are all the same 4.8-6.0

OK, I have a plan of attack and would like an opinion or two.

I found a 2004 model truck motor with FBW (fly by wire) for a real good price. I plan on using the wiring harness, cutting out the FBW circuit and adding a IAC (idle air control) circuit and TPS (throttle position sensor) circuit then running an older model computer. Obviously i would have to use a cable throttle body from another 6.0 or 5.3 to make it work.

Comments?

Suggestions?

Thank you,

What PCM are you using????

The 2004 model PCM will come with the motor.

I propose using a PCM from a year model that came with a cable throttle body.

2002-2003 can be programed both ways... not sure on the 04, you would have to find a bin that has a cable, I'm pretty sure all g.m were DBW by that point. What tunning software?

I think some 04 3/4ton vans had a cable throttle.You may be able to use that OS.

i will try to find a 02-03 PCM when i pick up the motor friday.

I planned on sending the computer off to have it programmed, but if you can recommend a software to me i may try to program it myself.

Thank you again,