Fast/LS2 install issue
Thread Starter
Melting Slicks
Joined: Nov 2003
Posts: 3,011
Likes: 9
From: Dublin GA
Fast/LS2 install issue
I finished up my FAST intake and LS2 TB install, but when I tied to fire it up, it showed "reduced engine power" I checked for codes, and there were three
P1120
P1220
P1516
All having to somthing to do with the TP sensor. I contacted the guy I got the harness from to see if he had any ideas, but if anyone else has any thoughts, I'd love to get this thing running. Tomorrow's SUNDAY!!
P1120
P1220
P1516
All having to somthing to do with the TP sensor. I contacted the guy I got the harness from to see if he had any ideas, but if anyone else has any thoughts, I'd love to get this thing running. Tomorrow's SUNDAY!!
Thread Starter
Melting Slicks
Joined: Nov 2003
Posts: 3,011
Likes: 9
From: Dublin GA
Here's an udate if it will help;
I unplugged the plug and play wiring harness from the LS2 TB, and plugged the LS1 TB back in (not mounted of course) with the original wiring harness and the codes clear (and don't return with the ignition on)
This leads me to believe that the issue is either with the wiring harness, or with the LS2 TB. The codes WILL set with the new harness just plugged into the orignial wires, but NOT plugged into the TB, if that makes any difference
Any help??
I unplugged the plug and play wiring harness from the LS2 TB, and plugged the LS1 TB back in (not mounted of course) with the original wiring harness and the codes clear (and don't return with the ignition on)
This leads me to believe that the issue is either with the wiring harness, or with the LS2 TB. The codes WILL set with the new harness just plugged into the orignial wires, but NOT plugged into the TB, if that makes any difference
Any help??
Former Vendor
Joined: May 2005
Posts: 3,749
Likes: 4
From: Valencia Ca
Look at the LS2 TB and note the connections "ABCDEF"
Check and match the plug& play cable ....it should match the scheme below - if not, change per schematic and you will be good to go.
A – Brown
B – Yellow
C – Green
D – Blue
E – Purple
F - Pink
White & Yellow w/ blk stripe = Not Used.
Check and match the plug& play cable ....it should match the scheme below - if not, change per schematic and you will be good to go.
A – Brown
B – Yellow
C – Green
D – Blue
E – Purple
F - Pink
White & Yellow w/ blk stripe = Not Used.
Thread Starter
Melting Slicks
Joined: Nov 2003
Posts: 3,011
Likes: 9
From: Dublin GA
Thanks CW
That is what I have in the TB harness. Is it possible that I have a bad TB? Are they repairable (for less than a new one)
I bought this one a "new" from a forum member (on the "other" forum)
That is what I have in the TB harness. Is it possible that I have a bad TB? Are they repairable (for less than a new one)
I bought this one a "new" from a forum member (on the "other" forum)
Drifting
Joined: May 2002
Posts: 1,607
Likes: 1
From: San Francisco CA
Originally Posted by BOTTLE FED
The codes WILL set with the new harness just plugged into the orignial wires, but NOT plugged into the TB, if that makes any difference
Any help??
Any help??
Have you tried running the car or clearing the codes?
Former Vendor
Joined: May 2005
Posts: 3,749
Likes: 4
From: Valencia Ca
Originally Posted by BOTTLE FED
Thanks CW
That is what I have in the TB harness. Is it possible that I have a bad TB? Are they repairable (for less than a new one)
I bought this one a "new" from a forum member (on the "other" forum)
That is what I have in the TB harness. Is it possible that I have a bad TB? Are they repairable (for less than a new one)
I bought this one a "new" from a forum member (on the "other" forum)
Good luck,
Charlie
Thread Starter
Melting Slicks
Joined: Nov 2003
Posts: 3,011
Likes: 9
From: Dublin GA
Originally Posted by SFVetteman
The codes are supposed to set if you have the key on with the wires not connected to the TB.
Have you tried running the car or clearing the codes?
Have you tried running the car or clearing the codes?
"Check the connections and make sure there is continuity. I've had more than one bad adapter. "
I have plugged and unplugged the TPS adapter and main adapter several times with the same results. Is there any votage check I can do that will confirm whether or not it is the harness?
That's why I asked if it COULD be the TB. If that's not an option, then I will just get another harness since it gave no codes with the old TB plugged up (with no harness involved)
Thaks for the help guys
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
Try a post on the C6 forum to see if anyone has the diagnostics for the throttle body motor itself. If the harness pins out correctly, and the car doesn't code with the original TB, that is where I would look next.
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Drifting
Joined: May 2002
Posts: 1,607
Likes: 1
From: San Francisco CA
With the key off, connect the adapter harness to the original harness and the LS2 throttle body. With the key on and engine off, reset the codes. Then start the car and see if the codes come back.
If the codes come back then using a DMM (digital multi meter), check for resistance (should be zero) of the individual wires in the adapter harness to see if there is continuity. Also, check the connectors and the adapter harness and LS2 throttlebody for signs of damage.
If the codes come back then using a DMM (digital multi meter), check for resistance (should be zero) of the individual wires in the adapter harness to see if there is continuity. Also, check the connectors and the adapter harness and LS2 throttlebody for signs of damage.
Thread Starter
Melting Slicks
Joined: Nov 2003
Posts: 3,011
Likes: 9
From: Dublin GA
With the harness hooked up, when I switch the car on, It will not let me clear the codes. Each time I reset, they re-appear immedietly.
I will check each wire in the harness for continuity when I get home and post results.
The TB looks like it is new. It literaly does not have a scratch on it.
Thanks
I will check each wire in the harness for continuity when I get home and post results.
The TB looks like it is new. It literaly does not have a scratch on it.
Thanks
Drifting
Joined: Apr 2004
Posts: 1,530
Likes: 250
From: CT
Sounds like your TB has a bad throttle position sensor. I ran into this same problem (immediately went into reduced power mode) with a new aftermarket billet TB that had brand new GM throtle position sensor and actuator. Turned out the new throttle position sensor had a dead spot somewhere through it's travel range and the ECM shut the engine down.
Replaced the TPS and all is well.
Hope this may help.
Replaced the TPS and all is well.
Hope this may help.
Thread Starter
Melting Slicks
Joined: Nov 2003
Posts: 3,011
Likes: 9
From: Dublin GA
HTFUN
I will be checking the harness when I get home, but from what i've seen so far, it is looking like the harness may be ok. If so, that would mean the TB is indeed bad.
Where did you get the TP sensor, what was the cost, and how hard is it to install?
Thanks
I will be checking the harness when I get home, but from what i've seen so far, it is looking like the harness may be ok. If so, that would mean the TB is indeed bad.
Where did you get the TP sensor, what was the cost, and how hard is it to install?
Thanks
Thread Starter
Melting Slicks
Joined: Nov 2003
Posts: 3,011
Likes: 9
From: Dublin GA
Originally Posted by SFVetteman
With the key off, connect the adapter harness to the original harness and the LS2 throttle body. With the key on and engine off, reset the codes. Then start the car and see if the codes come back.
If the codes come back then using a DMM (digital multi meter), check for resistance (should be zero) of the individual wires in the adapter harness to see if there is continuity. Also, check the connectors and the adapter harness and LS2 throttlebody for signs of damage.
If the codes come back then using a DMM (digital multi meter), check for resistance (should be zero) of the individual wires in the adapter harness to see if there is continuity. Also, check the connectors and the adapter harness and LS2 throttlebody for signs of damage.
The voltage readings were;
Green - 5.02
Yellow - .005
Brown - .005
Pink - .018
Purple - .018
Blue - 5.11
Is it the TB???
Drifting
Joined: May 2002
Posts: 1,607
Likes: 1
From: San Francisco CA
We know the original harness is good as it works with the old TB. Since each of the wires in the adapter wires are good and if the pins on the adapter harness appear to be undamaged or coroded then it must be the TB 
