I have read and read and read for about the last three weeks to start off. I'm to the point where I'm lost and if someone can point me in the right direction it would be much appreciated!




Here we go...I have a 99 FRC with a fresh LQ9 416, LS3 top end with holley hi ram 105 and nick Williams 102. ABS has been deleted. still 6 speed. PCM was sent to Shortunning for a start up tune and nothing has been changed since I gave them the list of mods done. I did purchase the car as a roller so it has never ran until now.


After chasing issues for the last few weeks, I have finally heard the car run for the first time today. The shop that built the motor used the wrong cam gear on a 58x reluctor, when they were suppose to use a 24x. After finally figuring out the issues I installed TRG002 Lingenfelter box, NOW IT RUNS.....only until it starts throwing codes and goes into reduce engine power. When the car goes into reduce engine power you can no longer give the car throttle and eventually the car will die in seconds. The car seems to run great the first few seconds. Any help would be awesome, thanks.






here are the codes: PCM p0443 c
PCM p1514 H C
PCM p1571 H C


TCS no comm.
SDM U1040 H C
radio no comm.

 

Wow, wrong reluctor. That really sux. This might help on your 0443 code. https://www.corvetteforum.com/forums...ode-p0443.html Here's some more good reading and looks like a fix for the p0443. http://www.arizonacorvetteenthusiast...c/14490-p0443/ The 1514 and 1517 codes are both related to the TAC and are what's causing the reduced power mode. With the NW 102 you're just going to have to iron that out. It's all pretty custom and you need a tuner to look at your car. I have some questions on your TB. What adapter harness did you use? Is it home made or other? I have an LS3 but had the reluctor changed to the 24x when it was being built. I have a FAST intake with an LS2 TB and the adapter harness from Casper. Wish I could be of more help but first thing I'd do is take it to a tuner that knows C5 Corvettes. Not being able to see it only allows for a few educated guesses. GL and please keep me informed on how its coming along.

 

Thanks for the help, I'm going to email the tuner today and see what can be done. It makes sense on the evap because after searching I don't have that anymore and it needs to deleted on the PCM. I also don't have traction control anymore.

With it throwing the code for the evap, would that make it go into reduced power and throw the codes for the NW102?

 

Thanks guys! I'm going to email the tuner and see what he says on trying to fix it.

I also dont don't have a evap on the car and need to have him turn it off. Would the evap code also cause reduced engine power and make the TB go out of wack?

I used a caspers wiring harness for the TB.

Hopefully I can send my PCM out again bc the tuner is almost 4hrs away from me. At this point I just wanna get it running so I can heat cycle the motor and do a break in process. Thanks for the input and pointing me in the right direction!

 

Good catch there Chuck. Darn ol' man eyes....

 

DTC P1514 Throttle Body Performance
Circuit Description
The PCM uses the TP, the BARO, the IAT and the engine RPM in order to calculate an expected Mass Airflow rate. The PCM compares this value to the Mass Airflow value and the speed density calculation in order to verify the proper throttle operation.

Conditions for Running the DTC
DTCs P0601, P0602, P0606, P1515, P1516, P1517, P1518, P1624 are not set.
DTCs P1120, P1220 and P1221 are not set at the same time or DTCs P1120 and P1220 are not set at the same time.
Engine operates longer than 1 second.
Engine speed is greater than 500 RPM.
Conditions for Setting the DTC
The PCM detects that actual airflow (MAF) and Speed Density is much greater than the expected (calculated) airflow rate.
All above conditions met for less than 1 second.
Action Taken When the DTC Sets
The PCM will illuminate the Malfunction Indicator Light (MIL) when this diagnostic runs and fails.
The Reduced Engine Power message displays on the drivers information center.
The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Freeze Frame and/or Failure Records.
If no other TAC System DTCs are set, the TAC System operates in Reduced Engine Power mode, and this DTC will be stored. If certain TAC System DTCs are set at the same time, the TAC System either defaults to a more tightly restricted mode of operation if the TAC determines that limited safe operation is possible, or the TAC commands the engine to shut down.
Conditions for Clearing the MIL/DTC
The PCM turns the MIL OFF after three consecutive drive trips that the diagnostic runs and does not fail.
A last test failed (Current DTC) will clear when the diagnostic runs and does not fail.
A History DTC clears after forty consecutive warm-up cycles, if this or any other emission related diagnostic does not report any failures.
The PCM battery voltage is interrupted.

Important
The clear DTC info function may have to be performed twice in order to clear a Throttle Actuator Control System DTC.


Clear the MIL/DTC information using a scan tool.

 

The Reduced Power (REP) deals with the actual throttle blade position sensor data, Accelator Peddle sensor data, MAF Air Flow issues vs TB Predicted Air Flow.

You either have a Throttle By Wire system issue or the tune doesnt like the actual vs predicted air flow.

NO,,,,,, The EVAP or EBTCM will not cause REP

 

I talked to my tuner and he told me to try a different TB for now. I purchased a ls3 stock TB and gonna try that, should come in mail within a couple days.

 

Gee... Please ask first. Bunches of us have been down these roads. LS3 TB won't work with your computer. The blade goes the wrong way from what I've heard. There are a variety of issues with the LS3 TB. You need an LS2 TB, the one with the silver blade, not the gold blade. They're more expensive as well.... Many threads about this issue. See if you can stop the shipment.

 

Great....I'm sure I can sell it again. I'll probably have to purchase a new one, I don't think there are any used ones on the market right now. I'll post something.

 

https://www.corvetteforum.com/forums...y-on-a-c5.html Maybe you can persuade HPS Master Tech to tell us the secret to getting one to work. It would sure save us a ton of $$ if we could figure it out.

 

That would be nice!!! I already have the 102, a ls3 on the way and now looking for a ls2....

 

Several for sale in the for sale section:

https://www.corvetteforum.com/forums...ttle-body.html
https://www.corvetteforum.com/forums...ttle-body.html
https://www.corvetteforum.com/forums...nd-ls2-tb.html

 

thanks, just purchased one from CYP65

 

FWIW the LS3 blade opens the same as LS2.
The diff must be in what the internal TPS sensors report to the TAC module.
Wish I had one to play with.

 

the answer has been released. search for my post

 

i accept donations!! lol

 

Sounds simple enough, I’ll try it this weekend and see what happens with it! Might just burn the whole car down with it!

 

ive been running with it for 700 miles now and multiple dyno pulls

 

For those who cant find the post:

https://www.corvetteforum.com/forums...y-on-a-c5.html

THANKS HPS

Bill