2003 2500 silverado code P1516 TAC Module

[Mike_Burak]

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]

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]

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.

1. <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.
2. 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]

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]

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]

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]

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]

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]

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]

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]

I also think it is the air box.

[chevyp2p]

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]

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 there

[j cAT]

Originally Posted by cm1

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 there

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

[2eyefishclaw]

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.