Tps won't go pass 30%

[Ernie@vindictive]

05 gto engine swap. With the key on tps goes to 88% but once it's started it will only go 30%????

[IDRIVEAG8GT]

Engine swap to what? What all was done?

None of us have a crystal ball.

[Ernie@vindictive]

put a Ls2 out of a 05 gto into a Hummer with a 4l80e trans. had to use a truck intake with the ls2 dbw throttle body. had to replace the pedal because the app2 was dead(the small wire came apart inside). got it fired up today and with the pedal to the floor the tps read s 30-32% and rev slow. so pulled the intake off to make sure that the throttle was only opening 30% and sure enough only barley cracking open. with ign on and the vehicle off it works normal.

[IDRIVEAG8GT]

Ok, sounds to me like your pedal is mismatched to that series ECM.

Is it going into REP mode?

[Ernie@vindictive]

The only code I'm getting is lost comm with Tcm, I don't think it's going into rep mode wouldn't it throw a code for that?

[IDRIVEAG8GT]

The only code I'm getting is lost comm with Tcm, I don't think it's going into rep mode wouldn't it throw a code for that?

Well, that's basically what Reduced Engine Power mode is. At 100% throttle I think you get only 9% opening over idle which would put you at that 30% throttle input.

The TCM communication error needs to be fixed first. Unhook battery for 15 minutes, or pull TCM fuse for that amount of time.

[Ernie@vindictive]

Well, that's basically what Reduced Engine Power mode is. At 100% throttle I think you get only 9% opening over idle which would put you at that 30% throttle input.

The TCM communication error needs to be fixed first. Unhook battery for 15 minutes, or pull TCM fuse for that amount of time.

We r using a 08 van os to control the 4l80, bill from hp said it should work.
Wouldn't it set a code for REP mode

[IDRIVEAG8GT]

We r using a 08 van os to control the 4l80, bill from hp said it should work.
Wouldn't it set a code for REP mode

I know this is going to sound uneducated but, to me it sounds like it is in REP mode, but is throwing a code the scanner can't recognize.

The reason it's in REP mode is because the ECM and TCM series aren't jiving.

Bill or Chris can either of you two chime in? This isn't my area of expertise.....

Also in this case you might need a Tech 2 to tell you what the BCM is saying.

[Texas_AT]

Back to the top. Found this thread in a search, having exactly this issue in an E67 Swapped LS2 setup. All is good, every other start I get the 30% max throttle and slow revving with TB cracked. Mine is a 2 bar maf-less OS. Shut down and restart and I get full throttle again. It's not setting a reduced engine power code, and not having the original dash or display to say it's in REP mode, I can't be sure. But it's doing EVERYTHING the OP's application is doing.

[Montecarlodrag]

You know it's in REP mode if it barely revs even when you flor it. Shut down and restart and it revs good until it trips the REP again. It's normal not to throw a code at all.
To avoid this the best solution is to get a pedal/TB 100% compatible with the ECM and OS you have

[Texas_AT]

Pedal, ECU, Throttle Body all from same vehicle, installed into transplant vehicle