2003 2500 silverado code P1516 TAC Module


Mike_Burak
12-15-2007, 09:48 PM
My truck is an 2003 2500hd with the 6l engine and 89k miles. From time to time I'm getting message "reduced engine power". Usually at the morning after 10-15 minutes after starting. I have to pull over, shut it off, wait few seconds then restart it. The ses light goes off usually by end of the day ( or after few hours ). When scanned by chevy tech showing code P1516 Throttle Actuator Control (TAC) Module Throttle Actuator Position Performance. I have new battery with new main cable. TAC Module was cleaned. Need some help with this issue. Thank you.

isie
12-15-2007, 10:39 PM
I went thru this very same thing. I took it to 3 different dealers and nobody could figure it out, had it cleaned 3 times and never helped.Mine di it whenever it wanted, no rhyme or reason, no set pattern. I finally talked to a GM tech that lives next to my father in law and he said that I needed a new tac Throttle actuator control. all three dealers told me that was not my problem, and if it is changed you need the tech 2 to recalibrate it. You do not need anything to calibrate it it just plug and play takes about 5 minutes. I changed it after doing all the stuff that was recomended and so far so good, there is a yellow wire going into the tac that brakes alot, mine wasnt. The guy that told me to change it got it for me from the dealer at his cost which was $156. I looked it up on gm parts direct and they where actaully a little cheaper. I can look for the receipt and get you a part number. if you have any questions email me and I will email you my phone # if you want.

brian 1
12-15-2007, 11:18 PM
after reading both problems just thought i would pass along this info.found this bulletin.#1869994.you might want to check this also.A vehicle may be brought into the dealer for a reduced power message, and DTCs P0120, P0220, P1516, P2101, or P2135.
The Throttle Actuator Control (TAC) / throttle body type trouble codes, may be caused by a loose wiring crimp at the throttle body connector, or a broken throttle body circuit.
<A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=1869994&psdid=297&evc=sm#ss2-1869994">Recommendation/Instructions:

Complete the current SI diagnostics for any symptoms or trouble codes found. If a intermittent T/P or TAC module type code is occurring complete the inspections below.
<LI type=1>Inspect all related throttle body terminals for a loose wiring crimp. The loose crimp may be difficult to find, and the poor connection will be between the terminal and the copper strands of the wire. Wiggle test the individual throttle body circuits to see if the concern can be duplicated. <LI type=1>Inspect the related circuits for broken wires inside the insulation. The outer wire insulation may look fine, but the internal copper strands may be partially broken. Breaks in the wires usually occur within 1 to 4 inches of the throttle body connector. Wiggle testing may also induce a trouble code to set.
On C/K trucks complete SI procedures for voltage drop on grounds G103 and G104. Grounds G103 or G104 may be loose or corroded. just thought of a little fyi.

isie
12-16-2007, 02:58 PM
I went thru the whole bulletin and so did all 3 dealers and mine was a bad tac.I would go thru it like brian 1 says but if all checks out I would then change it. I should have changed it instead of going to the dealers who only did what I did and charged an arm and a leg.

Mike_Burak
12-18-2007, 06:39 PM
Thank you for your respond. What I also noticed is: ses showing error after starting truck, quick warmup and driving same distance .Usually I'm using same road and getting ses message in the same spot on my route, strange? Is this connected somehow to the engine temp?

skinfox
01-13-2008, 06:07 PM
I am haveing the same problem with my 03 silverado but it will only do it when I have the throttle open all the way and right when it is going to shift. I have a BBK throttle body on it and a Volant intake. I didnt have the problem untill I installed these tho. Coule changeing the tac moduel solve this?

isie
01-17-2008, 10:51 AM
skinfox I would take both of them off and see if it changes, worth a shot, from what I understand on how these tac work the spacer doesnt rally do anything. on a tbi they would but here I dont think they do, just my thought I could be wrong.

stumped8159
12-13-2008, 02:12 AM
I'm new to this forum so if I'm not doing this correctly I appologize. My husbands 2003 chevy silverado is doing the same thing. After he gets a reduced engine power warning, the gas pedal does absolutely nothing. On the advice of a mechanic he replaced the computer, it still did it after that. He then said he needed a new Tac modulator so he got that and it still does it. When he hooked it up to the computer it tells him its the gas pedal sensor, so he bought a new one of those and it still does it. He installed all of these things himself this "mechanic" didn't do any of it. So, we dumped about $700 into trying to fix this problem and previous posts I've read stated that is could just be a wire on the tac modulator,my husband's not a happy camper but he's going to give it a try. We did get a letter from Chevy about the panel cluster problem and we haven't had any problems with it until recently, both problems occured aroung the same time. Could that have anything to do with it? We live in northern minnesota so the daytime highs are about 10 above and it gets to about -15 below at night. The cold weather is pretty hard on our cars but problems usually don't occur until it gets to about -25 below. I was just wondering if that could be a contributing factor, we never had any problems last winter so I doubt it. If anyone has any other suggestions we would really appreciate it.

j cAT
12-13-2008, 08:17 PM
this tac was a problem when the vehicles first came out with this system.

GM'S standard guide is to insure all wires and connectors are sound. this is good troubleshooting practice. then replace the tac...I doubt the pcm/computer had any problems too bad ...

you should start a new post and tell your husband that its something we all go thru learning how all this works...Before doing any work on equiptment like this,, a shop manual is best..this will if you have the abilities reduce wastful spending on parts that you don't need.. and keep your vehicle in top running condition...good luck...

perhaps a fellow member has other helpful ideas with this ..

thor72
02-20-2009, 08:24 AM
stumped8159, i did some research on this. if your husband repaced all the sensors and checked all the wiring. it could be in the air box. one forum said if you live in northern climates the box gets full off snow or trash and causes poor air flow which could cause the truck to show low engine power. i think chevy makes a repacement box for this condition hoope this helps you.

carmania11
02-21-2009, 06:25 AM
I also think it is the air box.

chevyp2p
07-23-2009, 01:32 PM
I also had a speedometer problem in my 2004 Chevrolet Silverado
the speedometer was not working at all and I found a website where I had it fixed. They charged me $140 to replace all the 7 motors inside the cluster That was a lot cheaper than the $700 that the dealer wanted to replace the instrument panel.

Here is the website
in case you want to check it out: http://www.speedometergaugerepair.com

cm1
09-05-2009, 09:04 AM
Hi guys,
I'm a small independent shop tech with 25 yrs. experience.
I had a 03 2500 with a 6.0L come in on the hook yesterday , no start after loss of power. It started right up and ran fine for me with no codes. On a road test it started acting up and ck eng light flashed .
Before shutting off hooked up scan tool and tac to pcm serial bus circuit code(I can't remember P code number I'm getting old). and low power message.
We use all data for the shop .
I did the pin point test for the code and actually found that someone had broken the lock tab for the connector from the tac to the throttle body off the tac module itself . and on rough roads and heavy load it would vibrate
and loose connection, I wire tied the connector into the tac and road tested it worked fine.
So what I'm getting at (after much ado) is sometime you have to look for someone else's screw up, and sometimes keep it simple.
I hope this might help someone out therehttp://www.automotiveforums.com/vbulletin/images/icons/icon7.gif

j cAT
09-05-2009, 10:38 AM
Hi guys,
I'm a small independent shop tech with 25 yrs. experience.
I had a 03 2500 with a 6.0L come in on the hook yesterday , no start after loss of power. It started right up and ran fine for me with no codes. On a road test it started acting up and ck eng light flashed .
Before shutting off hooked up scan tool and tac to pcm serial bus circuit code(I can't remember P code number I'm getting old). and low power message.
We use all data for the shop .
I did the pin point test for the code and actually found that someone had broken the lock tab for the connector from the tac to the throttle body off the tac module itself . and on rough roads and heavy load it would vibrate
and loose connection, I wire tied the connector into the tac and road tested it worked fine.
So what I'm getting at (after much ado) is sometime you have to look for someone else's screw up, and sometimes keep it simple.
I hope this might help someone out therehttp://www.automotiveforums.com/vbulletin/images/icons/icon7.gif

It is common for the connector to cause these codes....
no locking tab is on any componet trouble...

2eyefishclaw
07-02-2010, 06:22 PM
Open the engine harness from the tac to the pcm using about 3-5 lbs of force tug on each of the tac wires you may find one or more wires broken inside of the insulation. The wires are all to small for the circuit.

j cAT
07-02-2010, 08:56 PM
Open the engine harness from the tac to the pcm using about 3-5 lbs of force tug on each of the tac wires you may find one or more wires broken inside of the insulation. The wires are all to small for the circuit.


If the TAC is causing reduced power it is usually the connector/pins corroded ...then its the intake manifold throttle body , that must be replaced on these 2003 models...this is because it is a total pkg......

your wire failures are interesting ... On these you have seen this ???

rond201
07-02-2010, 11:13 PM
just replace the throttle body. my 2003 is fixed

Miller74
05-03-2011, 10:22 AM
If this module goes unchecked or not repaired for an extended period of time could it cause the truck to go dead. The reason I ask is I parked it on sunday and went to start it on monday with no luck of it starting. After replacing the starter I noticed that it thinks it is in 2nd. gear, while actually in park. Local dealership says it is a trouble code to keep the truck from starting.

cm1
05-19-2011, 01:57 PM
Hi and welcome
Yes this could lead to a no a start,the one I was working on would not start, but after having it towed to the shop it started right up.
When you say it didn't start what do you mean? It wouldn't crank or it wouldn't fire up?
Also it dose need to be fixed, because there will be a lose of power, and it could cause other problems.
Let us know what happens and how things turn out.

Good luck!!!!!!!:)

Miller74
05-19-2011, 03:41 PM
OK a little history. I was top of my class in automotive and after high school was a tire / lube tech with the promis of advancement. Low and behold went a differant direction and became a machinest and CNC repair tech. Long story short I believe in fixing things, not find and replace.
So my reduced power engine light started becoming a habitual acurance for me and I took it to the local repair shop. They said to me it was trouble code P1516 and that I'd have to replace my Throttle Actuator Control Module. $376.50 plus labor. So being the guy I am I blew up at the poor gal who told me this news and asked if they beleived in actually fixing cars or just replacing parts.:runaround: So dealing with about one hundred other proplems and wifes van. ( Hers gets fixed first:banghead: ) I let the problem go on figuring I'd deal with it down the road. So when the truck would not start that Monday morning I did the tipical old school checks. 1st. Turned key to start. Got nothing. Checked battery. OK. So remembering the older starters, I repeatedly turned the key to the start position. Slow and rapid. When I did it rapidly I got a sound that reminded me of a engine that was vapor locked. Wanted to but couldn't. So based on the clicking and sounds it made and advice from some friends of mine I replaced the starter. Well that was a waste of $150.00 But seeing that my truck has 130,000 miles on it figured not a total loss. So here I am puzzeled I made a few more calls. My buddy has the code check and wouldn't be able to come till the fallowing day. I noticed at that point that the trucks gear position read out display that went real dim about three years ago was showing my the truck was in 2nd gear. After a call to the dealership they said it was a trouble code as well as my auto tech friend:screwy::banghead: really! And after reading the post here I learned it could be a wire problem.:shakehead I love wires. Never thought my truck would have more dang wires than one of my CNCs. So I started at the fuse box under the hood. And guess what I found:disappoin At least 9 wires that the casing was rubbed off exposeing bear wires. After tugging and tapeing up all the exposed wires, I moved to the throttle body and tug tested all those wires. After tugging and taping went and tried starting the truck again. Nothing. The next dau my auto tech buddy came over with his computer and pluged it in. My truck spit out at least a dozen codes from transmission to other funky codes. He cleared out the codes and reset it. :naughty: The truck started. He let it Idle for a couple minutes and shut it down then restarted it a couple of times and then rechecked it for trouble codes. All faults were gone. :rofl: Conclusion. Bear wires in the bottom side of the fuse box may have been shorting out on them selfs. Do to years of driving ( since 03 ) vibrations caused exccesive rubbing and wear on wires exposing the copper strands causing shorts in the system. After wires were repaired and computer reset, I have not ( knock on wood ) had any problems.

j cAT
05-19-2011, 04:05 PM
the location under the fuse box is where rodents may nest and chew wires...my 2000 silverado had this occur ....the wires need be coated with liquid tape...then they need loom covering the insulted wires to keep the rodents from damaging them again...

the TAC low power failure is a / was a very common failure ...OEM defect in 2003 ....................

jreiter2
09-22-2011, 09:04 AM
I have similar problem with my 2003 silverado and would like to share my experiences. About two years ago I had one instance of the reduced engine power message and had to pull to the side of the road. While I don't remember the specifics I figured out that turning the ignition switch off and on several times cleared the problem. I had no other problems until last year when the same thing happened. Still didn't think much about it until now. Over the last two months I have had anywhere from one to three instances of the reduced engine power always in the morning when my lights were on. It never has happend any other time while driving...always in the morning with the lights on. About two weeks ago during the day my truck wouldn't start after driving it a couple miles and stopping to brwose for a few minutes at our local Home Depot. I went to leave the parking lot and the truck would not turn over. I jiggled the key switch, jiggled the gear selector to no avail. Finally when I turned the light switch from auto to manual lights on the truck started right up and hasn't happend since. So naturally I'm thinking my reduced engine power is related to the light switch in auto mode. Now when I go to work and it's dark I turn the switch to manual. For several days no problems then I got the problem with the lights in manual. I purchased a scanner and figured out that when this happens I get code P1516 (TAC). I have removed all connectors and used a good cleaner to clean all connectors. I've pulled on the TAC connector and wires while the engine was running and haven't seen the problem. Again I've only had this issue when the lights are on and am able to reset the code with the scanner. After reading all the other tips I plan to purchase the TAC and replace mine. Hopefully this fixes the problem.

j cAT
09-22-2011, 09:12 AM
with your vehicle you will require the replacing of the throttle body. the TAC is a non removable part...If you can do this with out this throttle body replacement post back the part number and how you did it .

jayeshseo
09-22-2011, 09:26 AM
Thanks for sharing your post with us.
I went through the whole bulletin and i found it as inspiration to me.
I felt aroung for some time that even I should have changed it instead of going to the dealers who only did what I did and charged an arm and a leg.

jayeshseo
09-22-2011, 10:11 AM
Thanks for sharing your post with us.
I went through the whole bulletin and i found it as inspiration to me.
I felt aroung for some time that even I should have changed it instead of going to the dealers who only did what I did and charged an arm and a leg.

jayeshseo
09-23-2011, 05:00 AM
Thanks for sharing your post with us.
I went through the whole bulletin and i found it as inspiration to me.
I felt aroung for some time that even I should have changed it instead of going to the dealers who only did what I did and charged an arm and a leg.

kdmarb
10-29-2011, 05:43 PM
I was plagued by this problem for most of a year, mostly in cold weather but it would also sometimes occur in warm weather after I had been running for more than an hour. Engine would suddenly go to "Reduced Engine Power" and I would loose all power, pull off, shut down for 20 seconds and then restart again. Everything would then be fine. After taking it to the dealer for the third time, he replaced the entire throttle body as well as a post catalytic exhaust sensor. Now appears to be running fine.

291,000 miles and going strong.

rpmferris
01-18-2012, 12:50 PM
Same problem with my03 6.0. Dealer re-pinned connector to throttle body. Found most of wires were just barely hanging on or the insulation was bad around wires. Ran fine for Day or so. Reduced engine power again. but only 1 code 1516. Going back into dealer going to check and clean grounds. Had DTC 0120,0220;1516;2135 before he re-pinned the connector. So helped a little bit i guess. Apparently low voltage to TAC module can trigger reduced engine power too. So good idea to check power supply (battery connections etc) + grounds.

j cAT
01-18-2012, 03:01 PM
Same problem with my03 6.0. Dealer re-pinned connector to throttle body. Found most of wires were just barely hanging on or the insulation was bad around wires. Ran fine for Day or so. Reduced engine power again. but only 1 code 1516. Going back into dealer going to check and clean grounds. Had DTC 0120,0220;1516;2135 before he re-pinned the connector. So helped a little bit i guess. Apparently low voltage to TAC module can trigger reduced engine power too. So good idea to check power supply (battery connections etc) + grounds.


tac failures 2003 are 110%...throttlebody needs replacing.

never use carb cleaner on this engine !

rpmferris
01-19-2012, 03:11 PM
Throttle body was replaced. Just the other day. Same thing happened. So that wasn't it. Thankfully they took it back off and didn't charge me for it.

j cAT
01-19-2012, 03:16 PM
Throttle body was replaced. Just the other day. Same thing happened. So that wasn't it. Thankfully they took it back off and didn't charge me for it.

replacing the connector and the throttle body is required..


wires with bad insulation is not normal ...this vehicle have a fire ?

carb cleaner could explain the damaged wiring.

rpmferris
01-19-2012, 03:21 PM
Nope no fire. But feel like setting it on fire if i can't solve this problem. Was getting 2135 code when i took it in. after re-pinning connector no code and worked fine with old throttle body on. Until morning just after start up bout 10 minutes into drive. Reduced engine power. Happened 5 times on me today on a 20 minute drive. its in dealer as we speak.

rpmferris
01-19-2012, 03:23 PM
No carb cleaner either. Don't use that stuff. Person in truck holding gas pedal down and brake clean on rag wipe out cabon inside throttle body.

j cAT
01-19-2012, 04:47 PM
No carb cleaner either. Don't use that stuff. Person in truck holding gas pedal down and brake clean on rag wipe out cabon inside throttle body.

the only product to use is throttle body cleaner on this engine.

TAC failures are in the begining very intermittent..when the TAC fails for a brief instant the reduced power comes on.. this is a safety feature to prevent runnaway engine like toyota issues.

connector defective means throttle body mounted tac is defective.

brake cleaner is for brakes.

wires are n/g , so how did this occur ? any ideas ?

rpmferris
01-19-2012, 06:13 PM
Sorry. Thats what i meant to say was using TB cleaner not brake clean. He tried the new throttle body complete with tps sensor on side and still did the same thing. Wish GM didn't try to re-invent the wheel sort of speak by going to this electronic crap. The older throttle cable stuff worked well. I realize it is a safety issue. But why pay a GM tech with all the "high tech" equiptment $100 per hour to run me around in circles. Obviously not all the reduced engine power stuff is caused by the same thing. Everyone has had a different thing solve their problem..Ready to drive her back into the dealer and say keep it. Gonna fix up my old 89 6.2 Diesel and run it. Take this piece of crap and burn it. Pretty bad that a computer and some wiring can ruin a perfectly good 50,000$ truck. Well guess someone has to keep all these guys employed.:jerking:

j cAT
01-20-2012, 09:29 AM
your problem is well documented on the internet. 2003 drive by wire was a very big problem [reduced power] .

like I stated before new connector and a new throttle body.

new throttle body does not mean its a good one.

2003 vehicle is too old for dealership repair. they do not wish to get this working for you because they make more money selling a new vehicle. I would not sell this vehicle because the new vehicles have transmission and engine issues.

have the connector and throttlebody replaced at another repair shop. this issue is well known by all in the auto repair business.

rpmferris
01-20-2012, 01:55 PM
That's great. Thanks for all your input. I will see how it works the next little while. Got word yesterday that there is another shop that has 2 Gm tecs Running their own shop. They both went into biz together. Got sick of the BS at the dealer and them ripping people off. Going to give them a crack at it if it continues. Two really good guys with a passion for trucks. Plus they have all the GM scan tools and the resources to find the problem. Will let you know how i make out. Thanks again.

j cAT
01-20-2012, 05:03 PM
That's great. Thanks for all your input. I will see how it works the next little while. Got word yesterday that there is another shop that has 2 Gm tecs Running their own shop. They both went into biz together. Got sick of the BS at the dealer and them ripping people off. Going to give them a crack at it if it continues. Two really good guys with a passion for trucks. Plus they have all the GM scan tools and the resources to find the problem. Will let you know how i make out. Thanks again.

sounds good to me ! when the owner operator is working on your vehicle most times the job will be to your satisfaction..

I used to work at a dealership.. evil..

rpmferris
01-29-2012, 01:56 PM
Ok, Hope u guys are ready for this. Coclusion DO NOT EVER TAKE VEHICLE TO GM DEALER!!!!! I am from small city where everyone knows everyone. If you read my other posts you will know the problem i was having. Come to find out the "Mechanic" who was "working" on my problem was a high school friend of my brothers. Swear GM mechanics are trained on how to screw people. Even if they know you personally. Anyway he spent 5 hours @ $100 per chasing around the problem just to keep me coming back. He supposidly cleaned the grounds on the truck that was posted on GM bulliten. Well i took it home took them off myself and it was done so poorly that i dont know how anything worked. He half assed cleaning the eye terminals and didnt touch the block with anything. I took pictures now going to have a fun fight with the dealer. Was in there 3 times $650 later still having same problem. He did do one thing that was good he re-pinned connector going into the throttle body. Well his next step was to replace TAC module. $600 from them. Well i went down street and picked up AC DELCO complete throttle body which they wanted $550 for got it for $250 tax in. I have to thank jCAt for also telling me that it should be cahnged. Any way long story short i fixed it myself in 2 hours and it hasnt missed a beat. I also cleaned the grounds properly and its like a new truck. People should NEVER go to dealer unless its under warranty. Though they will probably try to find something to screw you for.. Find an out source with the same equiptment . Most credible shops have high tech scan tools to find problems . NEVER GO TO DEALER. I am so upset that i have bought 3 vehicles from same dealer and this is how they treat me.?? i will NEVER BUY ANYTHING THERE AGAIN. I will pay twice the money and buy out of t

rpmferris
01-29-2012, 02:00 PM
Town. Thanks for listening to me and hope that this may help someone. And to all the GM dealer "mechanics" out there not sure how you sleep at night. This happens way too much to hard working people who go there for help and they drain you of every last penny you have and still have same problem. There may be some good ones out there but after 30 years havent seen any so far. Thanks.

j cAT
01-29-2012, 10:59 PM
Town. Thanks for listening to me and hope that this may help someone. And to all the GM dealer "mechanics" out there not sure how you sleep at night. This happens way too much to hard working people who go there for help and they drain you of every last penny you have and still have same problem. There may be some good ones out there but after 30 years havent seen any so far. Thanks.

well I am not surprised with the dealership screw job. trying to help you correct this easy common problem and you explaining the dealership taking hours of labor to figure it out was the reveal.

not all dealerships are thieves. most however are. easpecially when the vehicle is out of warrantee. the mechanic must create more labor/part expenses to keep the service manager happy with his cut on the take from you and others.

like I said I worked at dealership. its evil.. had to leave ...could not sleep.

good luck with your vehicle and keep it running as long as possible. use the forum to reduce these hassles.

rpmferris
01-30-2012, 04:30 PM
Thanks again jCat. Ya hope to get a little more out of the truck. will let ya know if there's anymore things i need some advice on.

Cackalacky
08-21-2013, 08:03 AM
Same thing, p1516 , low power.
We checked all connections to Throttle body - all good.
Mass Air Flow Sensor - unplugged this and the truck ran fine - no code. Test this 7 times with scanner. Each time the Mass Airflow sensor was plugged back in - got p1516 code.
Replaced Mass airflow sensor less than $100. Truck runs fine - no codes.

Will keep an eye on this and update if anything changes.

j cAT
08-21-2013, 09:55 AM
Same thing, p1516 , low power.
We checked all connections to Throttle body - all good.
Mass Air Flow Sensor - unplugged this and the truck ran fine - no code. Test this 7 times with scanner. Each time the Mass Airflow sensor was plugged back in - got p1516 code.
Replaced Mass airflow sensor less than $100. Truck runs fine - no codes.

Will keep an eye on this and update if anything changes.

the MAF causing the code is not something that I would expect.

when the throttle is varied the PCM uses this and all the other inputs to determine proper output. now normally when the TAC fails it will open causing an output to create this 1516 code. this is why the connector is also suspect with this failure.

The MAF if bad would throw MAF codes . could be someone damaged the small sensing wires and this may have created an error on the air flow into the engine confusing the PCM with what is going on.

Cackalacky
08-21-2013, 10:24 AM
Yep I didn't expect MAF, but since it was replaced there are no more p1516 codes. Only got code when the old MAF was plugged back in - repeated this 7 times.

Greenprecision
05-19-2014, 02:45 PM
So this is where I stand on my 2003 Chevy 2500HD 6.0L gas... I do not have a code reader but when I have got the codes read it has been throttle position mismatch(this is the weakest link in my journey on fixing the issue) I bought this truck last summer from a ford dealer. It had worked for a month before i started getting issues, it started off as random times under acceleration or deceleration or even when cruise control was on, someone had already replaced the connector end to the throttle body so I then replaced the original throttle body itself, this did not work either. So i took it to the GM dealer to have the software flashed $75 for that and it was done. That lasted for 300 miles, so i then switched the foot pedal out with another pedal and go nowhere, went back to the original pedal, I rewired with all new pins and new connector direct wires from the TAC module to the throttle body still did not work but now seems like heavy acceleration(Load). I then spliced in a ground coming from TAC module to frame ground with same results onder Load it goes into reduced engine power. Last thing I did was put a "new" TAC module on and it is still going into Reduced engine power under load when engine is warm.... about to completely set this on fire... last thing i am going to try is another new Throttle body and wire harness from foot pedal to TAC module. one other thing might be the mass flow as well. any one have any ideas i feel like I have touched every inch of the issues with the throttle body with no success

rond201
05-19-2014, 04:18 PM
New throttle body fixed my problem. GM should have recalled this long ago. The new issues with the switch shutting off is no worse than no power in traffic at 65 mph..............

j cAT
05-19-2014, 08:47 PM
the problem is with the TAC which is not replaceable . the throttle body need be replaced as a complete assy. also many have had issues with defective throttle body assemblies even GM dealership installed units !!!!!

the TSB was corroded connectors @the TAC ..fact is the TAC are defective.

never use any carb cleaner anywhere on these engines !!!!

good luck .

Greenprecision
05-20-2014, 02:15 PM
http://youtu.be/RPIujwkqfLo

Here's the YouTube video of what my throttle body is doing to me with high speed camera

j cAT
05-21-2014, 08:16 AM
http://youtu.be/RPIujwkqfLo

Here's the YouTube video of what my throttle body is doing to me with high speed camera

what company made this replacement throttle body assy ?

where did you buy this ?

Greenprecision
05-21-2014, 08:21 AM
NAPA, Don't remember brand off the top of my head

Greenprecision
05-21-2014, 08:26 AM
I am going to a local car/truck salvage place and taking a known good throttle body off of running 6.0L and see if I get the same results. I am curious with the way the throttle body works if the spike in voltage for opening the throttle that far is inducting into the sensing wires and making this happen... but I can not be the only one that will happen to

j cAT
05-22-2014, 09:24 AM
NAPA, Don't remember brand off the top of my head

should bring it back . many are defective clones.

ya scrap yard is a good idea. get OEM part.

Greenprecision
05-22-2014, 10:08 AM
so very angry! My brother owns a couple NAPA's and his part was defective and then Junkyard one off of an 05 6.0L full of carbon I had to clean out works like a top and didn't screw up no matter what throttle position I put at it hot cold and anything in between.... I hope never have to revisit this agonizing experience and 9 months of frustrations.

j cAT
05-22-2014, 12:09 PM
so very angry! My brother owns a couple NAPA's and his part was defective and then Junkyard one off of an 05 6.0L full of carbon I had to clean out works like a top and didn't screw up no matter what throttle position I put at it hot cold and anything in between.... I hope never have to revisit this agonizing experience and 9 months of frustrations.

so it looks like you did the correct thing and came here to get your vehicle fixed. good luck with your repair.

any time you need to repair electrical/electronic parts best check with the forums and see what others have to say.

My guess is the part you got from NAPA was cheaper. sometimes you can get to pay much more in the end...

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