k5383

iTrader: (10)

I'm swapping an 02 LQ4 into an 84K5, I built the harness myself. However, when I operate the gas pedal it fails to operate the throttle-body. I'm at a loss here, and quite frankly really considering throwing it all away and starting over with DBC.

Here is what I have, the silver aluminum backed TAC, all plastic TAC, 2 pedals, 2 throttle bodies, and one harness (TAC-pedal).

No matter the combination I make, the throttle body doesn't function. However, when I cycle the key you can hear it kick open/closed, with the plastic TAC the T.B. blades fight to stay closed (silver backed no resistance),but when I can physicallly move the blade by hand the engine reacts appropriately. When the key is in "run" but engine off, you can hear a high pitched whistle/whine from the T.B.

Anybody have any ideas as to where to start from?

k5383

iTrader: (10)

I should include, the harness came with the silver backed TAC.

As I sit here and research, I'm beginning to believe they're not compatible and that's my issue.

burbalanche

iTrader: (3)

computer tac and pedal all have to be from the same vehcle(all compatible).

MontecarloDrag

iTrader: (3)

you need a 2003 or newer operating system. Older OS won't control a dbw tb because the first dbw truck came in 2003.
You can flash another file to the pcm without problems, just don't mix 512kb with 1024kb
Post your current tune to check

k5383

iTrader: (10)

Couldn't tell you what my current tune is, bought the engine with the harness (blue/red) plug jackass gave me a green/blue ECU. I bought an ECU off a member on here, he assured me it would work for my 02 DBW and deleted some emissions/security stuff so I could atleast get it broken in and onto the trailer so it could be properly tuned.


I thought 02 was the first year? As 02/03 had the all plastic TAC? I could be mistaken, it was just my understanding.

MontecarloDrag

iTrader: (3)

If the PCM is Blue/Green then it is for DBW. The first DBW truck was 2003, 2002 and older are DBC and have Red/Blue connectors.

You can mix Red/Blue harness with Green/Blue PCM but a few wiring changes are needed. You need to have both diagrams to make sure all wires go where they should.

There are earlier cars with DBW but not trucks. Trucks began to come with DBW in 2003 AFAIK.

k5383

iTrader: (10)

Well, then I have no clue what this engine actually is.

I definitely have a red/blue harness, with DBW plugs, and it's most definitely a truck engine.. ha

I'll post some photos this evening.

MikeyZ

iTrader: (20)

2002 Escalade and corvette were dbw so the 2002 Escalade was infact the first dbw

k5383

iTrader: (10)

Fiddled around with it last night noticed something:

With the plastic TAC, and either pedal. I can hear a buzzing/high pitched whine from the T.B. also it fights to keep the butterfly closed.

With the metal backed TAC and either pedal, it doesnt buzz, nor does it fight me moving the butterfly at all.

I wired up the data port, and it never tripped any codes relating to the pedal?

Suggestions?

L_maddog

I have a 5.3l I put in a s10 and it came from a 2001 yukon xl and has dbw, I wouldn't even go this path with drive by wire, less wires less problem, I'm having this same problem in mine, I did the harness myself also but my throttle body actuator goes out sometimes, I reset the code it throws, which is code p1516 or p1518 and it comes back on till it the pedal goes back and I get no response, and also throws the same codes, I can get a flash for 75 bucks and find the wire connectors and everything else for dbc for around 200 bucks and it would sure beat te hassle of dealing with dbw

L_maddog

But what it sounds like with my computer being compatible with dbw when I push the butterfly by hand it doesn't react, I'd say ur computer is not setup for dbw

Thumper215

Close, but no dice. Here's a link with a thorough breakdown of the LSX systems. Read and read again. It is very detailed and answered a few concerns of my own.

http://www.lt1swap.com/dbw.htm

Best of luck.