Charlie@LsXperts

iTrader: (12)

Anything on this? Curious, I'm about to run an xlink with an ls3 tb

DrX

iTrader: (7)

Most of them are run with LS3 TBs now, and all are tested with LS3 TBs.

jschrock

iTrader: (7)

No, it's been raining/snowing here and cannot do a WOT. I will update when weather permits.

01WS6/tamu

iTrader: (36)

Is your aux fuel pump and water pump controlled by separate relays that draw power directly off the battery and not at the under hood power center.

What are you using to close the relay coils for each above device are they on toggle switch's or piggy backed into a 12v ign on signal from a fuse or wire directly on the engine harness or the underhood power center?

jschrock

iTrader: (7)

No, they come from the power center off the stud under the fuse block. They are controlled by the fuel pump wire from underhood power center. Attached wiring diagram exception I didn't go to battery, just the post under the fuse box.

Installed new TAC module, and no luck.... Programming autocal to get GM.ETCTP, GM.TPDES, GM.VOLTS and will report back.

01WS6/tamu

iTrader: (36)

Do you have your aux fuel pump relay trigger tied into the 12v signal that the pcm sends to the coil 12v of the factory fuel pump relay. OR do you have it tied into the output side of the stock fuel pump relay that sends power directly to the fuel pump.

You need to hook your aux fuel pump relay 12v coil trigger into the output of the stock fuel pump relay (fuel pump side) NOT into the 12v signal from the pcm that triggers the factory relay coil to close.

It could be noise introduced into the power system causing your problem. The power wire going to the UBEC is tiny compared to all of the circuits it feeds and the added load of these 2 high amperage noisy electric motors could be causing a low voltage and or noise situation that is present at the pcm causing the codes to develop.

I have had more than enough problems with weird gremlins that develop in police tahoes when they try pulling power off the UBEC instead of off the battery. You crank all the equipment up lights sirens radios wig wags strobes and headlights front and rear hvac and maybe windshield wipers and the pcms and bcm go ape **** with all kinds of driveability and semi false trouble codes due to low voltage. Move the power over to the battery and then run the relay triggers to the ign switch or the upfitters convenience center with a diode to prevent a backfeed and they work perfect.

jschrock

iTrader: (7)

I believe it is tied to signal that the PCM sends to the coil, but honestly I am not sure. I will have to look at the wiring again or find my manual. I did it by the instructions Magnuson gave in their manual. I appreciate all the advice and will definitely look into it.


Dr. X here are the logs you requested. One does not have a code, cannot remember which so I uploaded all 3.

DrX

iTrader: (7)

Your first log does not go into REP, but looks like you hit the rev limiter. Also noticed that your RPM and speed are dropping for a while after the shift while you are holding WOT....was it spinning in 1st and the top of 2nd? There are a couple of blips where the throttle does not hold 100%, but it does drop off enough to trigger REP.

In the other logs the TAC motor is not able to hold 100% and REP is triggered when the actual TP differs from desired/commanded TP by more than 7%. IIRC the TAC module should be able to draw 5-6 amps as required, which is more than enough to hold the throttle position.

Seems like an electrical supply/wiring issue if the same thing happened with another TB.

jschrock

iTrader: (7)

Yes, it was spinning.
The other TB was triggering a p2135, not the p1515. If it were a wiring issue, why didn't it do it with my 78mm?

DrX

iTrader: (7)

More current being drawn, more airflow. Did you try jiggling the wiring around key-on/engine off to check for an intermittent condition as you stated that this only happens when the engine is running and the truck is in motion?