I recently upgraded my mildly built LS1 with a new intake manifold and LS2 throttle body. After getting the car tuned, I’m getting a P1516 code repeatedly. A dealer scan found no anomalies at the time the code was set. The throttle body is working correctly from the scanner results. I get reduced power during periods of moderate throttle application. Any ideas of where to go from here?

 

What did you mean by “dealer scan”...a dealership looked at it or did you use a factory scan tool ??...if this is your scan tool I can tell you what you should see on both TPS signal wires...this is not the first time this has been reported here...sometimes it in the way the TB is wired !!!

 

u have to go to a specially tune shop to correct the parameters (hptuners, efi live etc...). Make sure your connection are clean and no bent porgs.. is it gold or silver plate?? This is a tuff one if the tuner doesn't have experience. dealer is no good in this situation because of the modified u mabe.

 

If it is not an actual GM LS2 silver blade TB then you will have issues.

 

Yes, if its not silver u will have a very very difficult time getting rid of 1515, if u even can.

 

It's either a dead spot in the TB electronics or loose/bad wiring.

Don't listen to the people above. I have been running a gold blade throttle body with modified harness for over a year now and no problems or codes. Over 3,000 miles. It CAN be done and CAN be tuned.

 

Why don't u read the whole response. Where in hell does it say he can do it?? I said I will be very very difficult. Not everyone is lucky as u. Where do u won't me to send u a trophy because u got yours working.
And u repeated what I suggested. Get ur S$#t straight..
where does it say to dump the gold plate TB?

 

Better yet get your panties out of a bunch. Calm down. Take a valium. Relax.

 

I had the car scanned by am GM dealer mechanic using a Snap-on Pro scan tool. He spent about an hour on the car. I know that he spent a lot of time working the throttle and all was well. He captured the parameters at the time the code was set and didn’t see any abnormality. He noted a 7% long term fuel trim on one ban with a 0% on the other. I pulled the spark plugs in the event that one of the new injectors was bad, All plugs looked the same, very clean with a light grey ground.

The throttle body is a Soler Engineering ported silver blade LS2 unit with the correct GM part number. The car has just been tuned by a very reputable tuner recommended by this site who was made aware of all mods on the car. The car ran perfectly before I changed the intake. The only changes made to the car since the last tune were the addition of a TPIS modified LS6 intake plus the LS2 TB. The tuner recommended larger 36 lb injectors since the injector duty cycles were up there with over 400 WHP. That is the total changes since the previous tube, when I drove the car to the tuner, I had noticeable on throttle surging and when I drove it back home I had off throttle surging. The tuner is several hours away so taking it back for a quick check is is not practical.

Yesterday, I cleared all codes, pulled the PCM fuses and conducted a throttle idle position relearning procedure since the idle was showing occasional dips. The last part of the procedure was to drive the car for at least 30 minutes. I drive the car 50 miles with no more than 30% throttle and only experience off throttle surging. Then after a couple of engine off stops, I put my foot to it I once in second gear and immediately got reduced power mode.I pulled over and shut the car off for two minutes. It restarted and drove normally but had set 9 codes. 5 were U codes. Here are the other codes:P1516, C1276, C1278, C2120. To summarize, the car can be driven all day without codes as long as WOT is avoided, 100% of the reduced power P1516 codes sets have followed WOT.

 

What the hell,how did u know i only wear panties on friday. . And by the way i take xanax and i ran out last i stopped taking valium years ago.

This forum is about getting as much knowledge from people that had different experience with similar situations so when somebody makes a comment like that to me is not helping. I in no way saying don't speak your mind. Again everybody has different experience. So it gives u options and different paths to success which this is whats it all about.

 

First thing don't worry about a 7% positive fuel trim...+ or - 10% is OK....if you have a DVOM and know how to backprobe a connector I'd check both TPS1 and TPS2 signal circuits on the TPS sensor with the key on...this is what you should see at idle and at WOT...this is with the engine off and you are looking at 4 voltages !!...there is NOT going to be 1 magic fix for this...you have to do some detective work. You can buy these T pins.

TPS1-IDLE

TPS1-WOT

TPS2-IDLE

TPS2-WOT

 

They are 2 separate issues. The surging just needs a better tune, Sounds like your MAF tables are possibly off.

The REP code at WOT only is a common problem with the gold blade TBs also. Your tuner needs to limit the max rotation of the throttle body to between 92 and 94%. At WOT the voltage goes out of range and you get the REP code.

 

Yeap good call. Hope that works but if it doesn't your going to have to head down different alleys or your going to be chasing your tail.

 

As a diagnostic exercise, I pulled the MAF connector to put the car in speed density mode. The surging was gone and I was unable to set the P1516 code after duplicating the conditions that reliably set the code. The car ran well. The only symptom in speed density mode is an occasional idle hunting. Is it fair to blame this on the lack of a MAF signal? The MAF is a descreened LS6 unit.I I am inclined to try a known un modified LS6 MAF to test whether the MAF is the cause of the code.

 

Can we see what u rigged up …….and how u rigged it ..what connections are you using ? Like most are explaining if your using a gold the circuit inside on the board may be a mis match to your wiring …some have taken the tb apart and reversed the polarity because the blade is most likely opening up wrong or someone obviously didn’t calibrate it correctly to your maf and that pulls low power mode …Hence this is why you should have got a a silver original or a Nick Williams which that’s what I use …..still they need to be set correctly I had only a small idle fluctuations never saw any codes ….


The code P1516 is is for the throttle position sensor. It looks like the car's computer is putting the engine in "failsafe mode" to prevent the car from being driven much further.


Meaning probably but not always due to the throttle body your running does not have the same polarity on the pcb circuit board as your stock body ….there’s been numerous write ups on how people have reversed the signal simply. The blade is opening up wrong , some have tried installing the unit in reverse or upside down …others have had to open the throttle body up and re rig two wires to reverse the opening process….hope this helps



If it was me I would have removed intake down to where I could see the plate and confirm which way the body is opening and how many degree the blade is at starting and log % at idle and a small toucc of throttle seeing your running a ls2 or whatever China knock off ! .Around 3 % on your is gonna be your ideal idle point ….I could help your more if you actually pick a a decent part for your 5 .