throttle becomes unresponsive at wot
Thread Starter
Teching In
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throttle becomes unresponsive at wot Was taking my chevelle on its maiden voyage with ls3/4l80e swap and ran fine until I hammered it on the highway and lost the throttle pedal. It kept running but there was nothing at the pedal. I pulled over and cleared the codes and the pedal was back. Tried it again, same thing happened. I had these three codes:
1. P0717-Input/Turbine Shaft speed sensor "A" Circuit no signal.
2. P0705-Transmission range (TR) switch circuit
3. U0140-Lost communication with body control module (BCM)
Now what would cause this? Bad sensors? Its a junkyard transmission. Or is it something with the wiring to the brake switch? It runs fine otherwise.
1. P0717-Input/Turbine Shaft speed sensor "A" Circuit no signal.
2. P0705-Transmission range (TR) switch circuit
3. U0140-Lost communication with body control module (BCM)
Now what would cause this? Bad sensors? Its a junkyard transmission. Or is it something with the wiring to the brake switch? It runs fine otherwise.
Thread Starter
Teching In
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PSI harness. I'm wondering if they put the wrong tune in it. I've double and triple checked the brake switch wiring. My order form says 2005 and up 4l80e. It's a late 90s trans (1999). So I think they might have tuned it for a 58x instead of 24x. Not sure that would give me those codes and dead pedal or not?
Lost throttle I had the same problem and it turned out to be a pedal/TAC/tune mismatch. Even had the U0140 code. Once I got the correct pedal/TAC everything works just fine. Go to the PSI site and see the two pedals they sell.
Thread Starter
Teching In
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PSI thinks it could be pedal but most likely TCC switch not wired properly. I've went through it and can't find any wiring mistakes. Would the car hesitate or show any other signs that the TCC is not locking/unlocking correctly?
Lost throttle I think the U code is the wrong pedal and causing limp mode where the other codes are unrelated to going into limp mode. I was able to borrow a pedal locally and solved my problem with the limp mode. Replace my '04 pedal with a PSI steel unit and all was well.
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I understand frustrating, but its all about how/what they do to resolve it. As long as they make it as painless and quick as possible, I call it a win. IMO, thats all a good reputable company can do, we are all human and mistakes happen.
Thread Starter
Teching In
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PSI has been outstanding. Didn't mean that to sound like a rip on them. I understand these swaps aren't always plug and play like people think. I'm just frustrated because I want tear some sh@! Up in my Chevelle!
I had a similar issue years ago but I cant remember the codes. Car would run fine until you got to about 80% throttle then it would go into limp in. My truck throttle body was not compatible with the Corvette OS that was in the ECM. Changed to a Corvette LS2 TB and the issue was fixed.
On The Tree
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Your ISS may be the cause of the issue if that is throwing the code. The ISS is located in front of your round trans connector. VSS is behind it towards the rear.
ISS issue is either in the tune, wiring, or a bad sensor. Verify the ISS and VSS wiring are in the proper location of the 4L80E. The VSS and ISS connectors are identical.
ISS issue is either in the tune, wiring, or a bad sensor. Verify the ISS and VSS wiring are in the proper location of the 4L80E. The VSS and ISS connectors are identical.
Thread Starter
Teching In
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Going on two weeks. While PSI's techs have been great, customer service has not been the greatest. I've been told 3 different times that it will ship next day and the most recent is "our tuner went home sick". I understand problems arise, I own a business but when it becomes routine to get promises and excuses and they don't happen....well it speaks for itself. Anyone recommend another company to work with? I'm ready to cut my losses. I have a big shiny turd sitting in my garage that needs some life.
On The Tree
Joined: Sep 2007
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If you desire an engine and transmission computer relfashed Speartech can support you. Or if you just want a new ECM/TCM to support your setup we can also set you up with new computer programmed for your swap. We can even get them out to you as fast as you need them. Usually within 1-2 days MAX of placing your order.
Give us a call and discuss your options. 765-378-4908 My name is Justin.
Give us a call and discuss your options. 765-378-4908 My name is Justin.
Thread Starter
Teching In
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Just got confirmation that it was sent late yesterday. Supposed to be here Thursday, so we will see. Justin thanks for your help, I actually have a ls3 crate being delivered via freight today for my 67' Bronco and will be calling for a harness package for it.