U0107, red/blue pcm, and dbw question
Probably normal readings. The throttle blade quickly closes then returns to the cranking position as part of the self tests when you turn the key-on...unless something else has already triggered REP before the self-tests run. You can definitely hear the blade snap closed and back.
Should be no power to the TAC module with key off. Otherwise it will try to communicate with the PCM, which has its processor powered down. The TAC module will store a U0107(loss of communication between TAC and PCM) that will already be there as soon as you turn the key on, thereby triggering REP.
Should be no power to the TAC module with key off. Otherwise it will try to communicate with the PCM, which has its processor powered down. The TAC module will store a U0107(loss of communication between TAC and PCM) that will already be there as soon as you turn the key on, thereby triggering REP.
Last few years they are optimized for the gold blade TBs, but LS2 silver should still work in most cases. Not too many using them though due to cost. Swaps/aftermarket harnesses are the worst to diagnose as far as REP situations, because I have no clue what is going on with the wiring without being there.
Thread Starter
Teching In
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Thanks for the suggestions. Installed a new TAC module and everything was the same. Was thinking it was the TB but it clicks with key on so I think that's fine, still not sure about the tps though.
Tried something weird and I think I might have found something.
I put a 2x4 under the throttle and it only takes about 1" or less of pedal travel to get to 4900 rpm, but no code no matter what I did. If I remove the 2x4 the pedal can travel much more.
Can allowing the pedal to travel more than intended result in U0107?
If so does this sound like a tuning issue or do I just need a pedal stop? I'd like more than 1" of pedal travel to WOT but making a pedal stop is about as cheap and easy as it gets so I won't complain.
Also, what is redline of a vortec 4800 LR4?
Tried something weird and I think I might have found something.
I put a 2x4 under the throttle and it only takes about 1" or less of pedal travel to get to 4900 rpm, but no code no matter what I did. If I remove the 2x4 the pedal can travel much more.
Can allowing the pedal to travel more than intended result in U0107?
If so does this sound like a tuning issue or do I just need a pedal stop? I'd like more than 1" of pedal travel to WOT but making a pedal stop is about as cheap and easy as it gets so I won't complain.
Also, what is redline of a vortec 4800 LR4?
Thanks for the suggestions. Installed a new TAC module and everything was the same. Was thinking it was the TB but it clicks with key on so I think that's fine, still not sure about the tps though.
Tried something weird and I think I might have found something.
I put a 2x4 under the throttle and it only takes about 1" or less of pedal travel to get to 4900 rpm, but no code no matter what I did. If I remove the 2x4 the pedal can travel much more.
Can allowing the pedal to travel more than intended result in U0107?
If so does this sound like a tuning issue or do I just need a pedal stop? I'd like more than 1" of pedal travel to WOT but making a pedal stop is about as cheap and easy as it gets so I won't complain.
Also, what is redline of a vortec 4800 LR4?
Tried something weird and I think I might have found something.
I put a 2x4 under the throttle and it only takes about 1" or less of pedal travel to get to 4900 rpm, but no code no matter what I did. If I remove the 2x4 the pedal can travel much more.
Can allowing the pedal to travel more than intended result in U0107?
If so does this sound like a tuning issue or do I just need a pedal stop? I'd like more than 1" of pedal travel to WOT but making a pedal stop is about as cheap and easy as it gets so I won't complain.
Also, what is redline of a vortec 4800 LR4?
There is always some extra travel in the pedal. You should check where the blade is when you are at 1" of pedal travel. If it is only partially open, you may eventually get to 4800 RPM, but you will have poor pedal response/acceleration.
So, you are saying that U0107 does not set immediately at key-on?
Key-on engine-off, if you move the blade by hand from closed to wide open will any codes set? (Also note how stiff the blade is to move by hand and whether it operates smoothly.)
If no codes set, there could be:
1) a wiring/ground issue: Do you read 0V between the battery negative and Pin 15 (black wire) of the TAC module 16 pin connector key-on and connector plugged in?
2) a bad/incorrect pedal. I would expect some pedal codes though if it was the wrong pedal. 2006 pedal should have the plastic lever arm.
If yes, U0107 sets, it could be:
1) The TB.
2) A bad TAC module is also possible.
Last edited by DrX; Jun 14, 2015 at 09:40 PM.
Thread Starter
Teching In
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Right, if I clear the code I can start the truck and even take it around the block with no codes. Once I floor it that's when the code returns.
If I disconnect and reconnect the battery and floor it I get:
U0107 Lost communication with throttle actuator
P0120 Throttle/pedal position sensor A circuit
P0135 O2 heater bank circuit bank 1 sensor 1
P0220 Throttle/pedal position switch B circuit
P1516 Tac module throttle actuator position performance
P2135 Throttle position sensor 1-2 correlation error
But if I clear those codes they don't return until the next time (except U0107) I disconnect the battery and floor it.
I have the pedal that's completely plastic.
My throttle body clicks at key on and operates smoothly with a bit of resistance.
If I disconnect and reconnect the battery and floor it I get:
U0107 Lost communication with throttle actuator
P0120 Throttle/pedal position sensor A circuit
P0135 O2 heater bank circuit bank 1 sensor 1
P0220 Throttle/pedal position switch B circuit
P1516 Tac module throttle actuator position performance
P2135 Throttle position sensor 1-2 correlation error
But if I clear those codes they don't return until the next time (except U0107) I disconnect the battery and floor it.
I have the pedal that's completely plastic.
My throttle body clicks at key on and operates smoothly with a bit of resistance.
