LS2 TB onto my 408 and now Codes, help
05-26-2008, 08:10 PM
#1
LS2 TB onto my 408 and now Codes, help I am trying to get this new ls2 TB to work, however, I get reduced power on the display and these codes (haven't started yet, and Vic Jr and elbow),
P1220-TPS Sensor circuit #2, according to HPT (GM manual does not state if it's TPS #1 or #2, but talks about both?)
P1221-fuel pump secondary circuit low, according to HPT (In my GM Z06 book it says it's the same as 1220, sensor circuit 1 or 2)
P1515-Electronic Throttle System Throttle Position, hpt and GM manual same
Trying to figure this out in diagnostics they all are related and send you back and forth in the manual? That 1221 and saying it's fuel pump seems to be a problem with HPT when scanning for DTC? Man, i don't know.
Anyway, seems I remember something similar to this being posted before and figured someone has the answer. Is the adapter cable wired correctly as this seems to have been mentioned before?
Also, I was getting a different batch of codes when the batt was a little more discharged,
p1120-TPS Sensor #1 according to HPT (no number like this in GM manual?)
P1220-TPS Sensor #2 according to HPT (GM manual does not state if it's TPS #1 or #2, but talks about both?)
P1221-Fuel Pump Secondary Circuit Low, according to HPT (GM manual has same description as code 1120 and non specific as to sensor 1 or 2?)
p1516 Throttle acuator Control and Module Throttle Acuator Position Performance, according to HPT and GM manual
I hope i didn't scare away potenial help here, lol, as it is a little confusing for sure.
Robert
P1220-TPS Sensor circuit #2, according to HPT (GM manual does not state if it's TPS #1 or #2, but talks about both?)
P1221-fuel pump secondary circuit low, according to HPT (In my GM Z06 book it says it's the same as 1220, sensor circuit 1 or 2)
P1515-Electronic Throttle System Throttle Position, hpt and GM manual same
Trying to figure this out in diagnostics they all are related and send you back and forth in the manual? That 1221 and saying it's fuel pump seems to be a problem with HPT when scanning for DTC? Man, i don't know.
Anyway, seems I remember something similar to this being posted before and figured someone has the answer. Is the adapter cable wired correctly as this seems to have been mentioned before?
Also, I was getting a different batch of codes when the batt was a little more discharged,
p1120-TPS Sensor #1 according to HPT (no number like this in GM manual?)
P1220-TPS Sensor #2 according to HPT (GM manual does not state if it's TPS #1 or #2, but talks about both?)
P1221-Fuel Pump Secondary Circuit Low, according to HPT (GM manual has same description as code 1120 and non specific as to sensor 1 or 2?)
p1516 Throttle acuator Control and Module Throttle Acuator Position Performance, according to HPT and GM manual
I hope i didn't scare away potenial help here, lol, as it is a little confusing for sure.
Robert
Last edited by Robert56; 05-26-2008 at 08:19 PM.
05-30-2008, 11:29 PM
#4
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It HAS to be the wiring adapter. Did you purchase the wire adapter LS1 to LS2 throttle body? One easy way to check would be log TPS readings....floor it and see if they go maximum....also check if the LS2 TB is opening and closing correctly. Thats my guess bad/incorrect wiring. I bought a harness and mine was just bascially plug and go....works perfectly on my FAST 90. (was too lazy to simply fab one myself). 
05-31-2008, 01:08 AM
#5
It sounds like the two TPS sensor signal wires are crossed. The two TPS sensors in the LS2 TB operate opposite of each other.
TPS 1: Signal voltage at closed throttle is above 4 volts and decreases as the throttle plate is opened.
TPS 2: Signal voltage at closed throttle is below 1 volt and increases as the throttle plate is opened.
Here is the pin out configuration for the LS2 TB. Ensure the wire colors are in the correct locations.
With the wiring fixed, all the DTC's should go away.
TPS 1: Signal voltage at closed throttle is above 4 volts and decreases as the throttle plate is opened.
TPS 2: Signal voltage at closed throttle is below 1 volt and increases as the throttle plate is opened.
Here is the pin out configuration for the LS2 TB. Ensure the wire colors are in the correct locations.
With the wiring fixed, all the DTC's should go away.
05-28-2009, 04:26 PM
#6
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p1120-TPS Sensor #1 according to HPT (no number like this in GM manual?)
P1220-TPS Sensor #2 according to HPT (GM manual does not state if it's TPS #1 or #2, but talks about both?)
P1221-Fuel Pump Secondary Circuit Low, according to HPT (GM manual has same description as code 1120 and non specific as to sensor 1 or 2?)
p1516 Throttle acuator Control and Module Throttle Acuator Position Performance, according to HPT and GM manual
I know this post doesn't really help you at all, but I figure misery loves company.
Edit: LOL, oops, just noticed the year on this was 2008.
...so I guess my question for the OP is: What was the problem?
Last edited by LT4Justin; 05-28-2009 at 04:35 PM.
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01-13-2011, 04:28 PM
#8
bringing this back from the dead i have the exact same codes after an ls2 tb swap with caspers harness, i have called caspers and they went over the harness layout and it is the same as all the other ones they have on the shelf, i checked continuity between all the pins and the harness seems good, so i unplugged the tb harness (6pin square) and checked pin D with the key on and it has 5v, i checked pin F and it shows 30v???
any suggestions? the guy from caspers says 90% of the problems are bad throttle bodies, this is an ls2 takeoff from a trailer blazer ss and the car runs, but has these codes...
any suggestions? the guy from caspers says 90% of the problems are bad throttle bodies, this is an ls2 takeoff from a trailer blazer ss and the car runs, but has these codes...
