I'm Susie's husband Bill. After 6 months, 2 dealers, $850 computer and throttle body clean my very frustrating intermittant problem still existed. Your tip led me to the problem and saved me $25,000 or so for a new truck- I will only add a pull tie applied nearest the plug made my every now and then problem an all the time problem and hence much easier to confirm a loose wire....and to then fix. Again Thank You so much!

Mr. Smith you are excellent! We just had this exact problem and your video helped find the broken wire (yellow one) and get the truck home to make the repair. You saved us hundreds of dollars in a tow and mechanic trouble shooting. Thanks.

Hey D-Ray I love you brother. Dealership wanted to replace my pedal, throttle body, everything when I read my codes To them. I have a Nissan and was getting code P2135 and P0223. Pretty much communicating miscommunication from the Sensors to sensors. I did the now famous “Tug Test” and found a wire loose from the sensor to the throttle body. You saved me close to wasting $1000 on parts in service the dealership was going to charge me when I ran out of ideas. Came across your video on one last desperate search through forums. Love you bro, keeps putting the content out.

This is great! Pointed me to the exact location and discovered I had several open connections. Not broken. but chewed on by some critter. Dismantled the connector and soldered the connections as shown and the problem is fixed. Thank you Don.

My friends and I were up in the mountains in California and the reduced engine power came on and we could not go more than 10 mph while we're were limping back to our cabin I looked up this video. We finally made it back checked the wires in the wire loom and it worked. Thanks for the help and Congratz on the 100th video

thank you so much. My husband is at his Christmas diner, he is a hvac forman, and I followed your instructions and got my GMC Yukon XL 8.1 to work and made the engine light go away. Now i just have to buy the replacement for the wireing before it goes out again. :)

This problem happened this evening while I was driving my 06 Chevy Silverado 1500 LT. I found this video, and found it VERY useful! I had no clue what was going on, after no acceleration, I then restart my truck and still no acceleration and the "check engine" light appeared as well the "Reduced Engine Power" light. Although I do not have the tools to fix it, it will be going into the shop, but I now have the understanding! Thank you! :)

Thanks D Ray! I had this problem on my way to work this morning. 5 degrees and ice on the road...that's not fun! Thanks for the video made my day better! God bless!

This was a great help. My 2003 Yukon with 166k miles triggered the REP warning three or four times a day last week and a DTC 1516. It turned out that my six year old battery was giving up and when I replaced it, the problem stopped. The shop manual says that one of the conditions that causes the DTC 1516 is when there is an irregularity with the vehicle charging system. The shop manual also says that 1516 forces the vehicle into REP or possibly for the engine to turn off. Sounds kind of dangerous, but I'm glad the problem was resolved. I went ahead and cleaned the throttle body and check the harness connectors anyhow. There was some carbon buildup, but everything looks good now. Thanks. .

Thank you for this video, my friends suburban was having the same issue. Dealership quoted him $700 for a new throttle body and your video saved him some serious money. We got the harness apart and found a bad wire. Trucks great now. Thank you

I'm having this issue with my 03 sierra denali. I'll look into when it warms up a bit. thanks for the video and damn it's nice to see a real/normal person making videos.

These are the best shade tree mechanic videos I have seen on here. Very detailded and easy to see everything. Makes it look easy to fix you vehicle. Thanks

Brilliant find, I am very impressed. Heading out to my 2003 Motor Coach with a Workhorse Chassis 8.1 Vortec right now to trouble shoot "Reduced Engine Power" P1516 code. You Da Man !!

Congratulations on 100 videos. You put things in perspective. Thanks

I forgot to mention, my Mechanic did come up with a P1516 issue, you were so correct. Thanks again

Hands down best repair video I've ever watched. Great explanation on everything thank you sir

I want to thank you for your advice, ever since I saw your video and took your advice was a blessing. I removed my throttle cleaned it as you describe and haven't had an issue since, I don't get that reduce engine code anymore, Thank You so much for this video.

i just wanted to say thank you this problem happened to me this morning dropping my son off at school i watched your video when i got home i checked the codes it was 1516 unfortunately my ( t a c) was bad i got two hundred and thirty eight thousand miles out of it thanks to your video i was able to find the problem and fix it myself

You are the man! I do believe I owe you a case of beer if you are ever in the Vancouver area. That's right, I had the dreaded 'Reduced Engine Power' scenario last weekend and got the codes read (P0120, P0220) by gm dealer, limped home and found black wire with white stripe broken inside? not week though? weird, it was nice and copper color. soldered in back up and looks good so far! Thanks!!!!

Thank you for taking the time to put this info out! I will try this myself (have error code P1518 and Reduced Engine Power) I'm sure the dealer would rather everyone come pay them $300 - $500 dollars instead of repairing it themselves.

Excellent video and explanation, these are the exact problems I just experienced. Thanks for doing a great job on this bud

That's real helpful, man! I'm having the same thing in my camaro and wouldn't you know it - they still use the same wiring connector 5 years later.

Hey thanks for the great video! My truck is a bit older with the throttle cables, but I really like the idea of the tug test on those harnesses. I got the exact same wheels too

I'm 12 years late to the video lol. My 2011 Avalanche is experiencing the same exact symptoms which comes and goes under a load which in turn causes my traction control to go haywire as well. I will be cleaning my throttle body while I'm in there but sure hope I find a loose connector. Thanks for sharing, much appreciated.

I love your southern accent, D-Ray. My 2007 Buick Lucerne has that "reduced engine power light coming on " three times recently, and I've had my mechanic change the throttle body itself, and that fixed the problem for about a month but the message came back. This time he changed an accelerator sensor and the problem went away, but sure enough, in another month the goddamned, fucking, bitching, dreaded "engine has reduced power" message was back on, much to my dismay. My mechanic had told me he suspected it may be a wire harness problem but that would "be a huge job to fix and could run me a $1000!) I contacted another mechanic who used to work on my car but had moved to another garage, not that far away, and told him about it and he said, "he'd look at it, but wasn't promising me anything.") The Lucerne only has 62000 miles on it and otherwise has been a good car. This video is like a god send, a wire harness is a $180 part? It doesn't look like it should cost me a grand to get it replaced. Tomorrow I'm bringing the car to this other mechanic and tell him about the wire harness problem as you have described in this great video. Thanks so much for this information, the last thing I need is to buy another car, I just can't afford it right now. I'll tell you one thing, no more GM vehicles. When I was a kid buying a GM car like Buick, Oldsmobile, or even a Chevy you were getting a piece of the rock. Not any more. My next vehicle will be a Toyota Camry or a Honda Accord, companies that know how to manufacture a vehicle properly, whereas GM evidently no longer does. Shame.

Great tip and video. On my 2003 chevy 2500hd it was the yellow wire. The insulation was intact on the outside but the wire was broke on the inside.

Very good info. I myself like to make my repairs to my personal vehicle as least costly as I can. Thanks my man and keep the info coming!!!

Congrats on your 100th vid! They are great.

Great video..About to try this on my 03 Suburban with 215,000 miles. Have a boat to pull out this weekend!

Congrats on 100 Buddy!! When ya gonna start showin' us the good ones!!☺

You rock Don! Thanks so much for posting this, you helped me sooo much!!

Great information and will continue to follow your free and generous advice. Thank you!

Awesome video man! My wife's 2006 cobalt is doing this

This guy is pretty darn good. Good repair man.

I have a 2001 chevy Silverado 2500HD 6.0L 2x4 6ft bed with a living camper on it and I have that issue going uphill for long distance. It goes about 20-30mph uphill and I don't want to push it any further, but on flat surface streets it runs strong and feels powerful. Going to look into this issue. I'm about to hit 200k miles on my truck! Happy camping!

Bro!!!!! You saved my life! Thank you so much

Thks D-Ray , Real Professional Videos.

Excellent video great job

Thank you sir you saved me a lot of money just by checking wires

It ruined my weekend.thanks for the video!

Thank you so much this really helped! You sir are the best next to my husband ;)

Thanks for the video you saved me $$$$$ on a garage fix you the man

I had to replace the wire harness on mine. The clip was broken and was loose causing the "reduced power". And I also replaced the TPS Sensor. The truck drove great for about a year now. But the "Reduced engine power" is back again. I'll have to recheck the wire harness again.

great info thx, it happended to me less than an hour ago on the highway ...pulling behind my friends car. If it happens again I'll know what to look for.

Thanks I have a 2008 Buick enclave and my truck I'd doing that me and my guy will be checking this out tomorrow we definitely appreciate it

great advice I started with your video...... ended up being spark plug missfire #3

thanks D-Ray. my 2004 Suburban had the same problem and fix -- jeff

Good video. I will check my wires on the harness.👍

I had this same problem what I did is cleaned my mass air flow sensor and it worked!!!!! Give it a try

Awesome video man!

Glad i watched this video. Got a truck like this one.

Thank you. That's exactly what I need to look at 😎

just spent $800 to get this fixed on my 2003 2500HD. Nice to know what was the reason for the failure.

very good, you save some money.. thanks from mexico...

You know how to make a video!!! Very informative. Great work D Ray!

Thank you for your very informative videos! :-) :-) :-)

As a retired electronic technician, I made many repairs similar to to this one on numerous industrial and entertainment equipment. This is an expected failure especially if the harness is connected to a moving assembly.

good administration , nicely done man

Dude you are great. Thank you much for your video,

Thank you Sir u really helped me with my problem

My Impala was slightly acting up at a red light every now and then. So I took the throttle body out and cleaned it. After I put it back it was down hill from there. I BET it's a wire. I can't wait to get back to it Friday after watching this I'm almost for certain it's something that simple

helpful information, thanks!

Mine only does this crap when it rains, snows, gets washed or if I drive in a big puddle.... 2007 Chevy Avalanche Thanks D-Ray for throwing this info out there!!!!!!!!!!

Man I'm so glad I ran into your video, I've been dealing with this problem for months, today replaced MAF sensor and nothing. So the loose wire theory got me thinking, I started poking here and there... and what do you know?! The problem is in the fuse box under the hood. Thank you so much!!

Great advice but do NOT force open the throttle body of an electric throttle body. I mean I don't know if this gm throttle body assembly is that tough (cough cough) but that is just as risky as starting a rotary engine and turning it or before it reaches is 3 stage warm up cycle (just a risk level example). Great vid I'm helping a friend out right now with this vid! Much appreciated. Any experienced gm techs. Care to verify if we can/should force it open? Or should we have a partner/friend depress the accelerator pedal from the drivers seat?

Very professional 👌🏼👌🏼

I have a 2004 V8 gas GM 2500HD, I had this exact same problem about a year ago. Ours was the black wire vs the grey but the same error code was there. Unfortunatly we replaced the throttle body and the pedal sensor before getting to this. Take his advice, the problem is usually the simplest failure. Save yourself the $1000.00 dollars in sensors and labour if you can.

Just wondering when you get that message does your engine temperature go to high ? That’s happening to my 2006 Montana and just doing some research hoping is not the engine

Very helpful and instructive video!

Ok , I pulled the connector off the TB and heard what sounded like a few relays inside the actuator housing? Should I have pulled the battery first and is this normal to hear?

i give my husband the tug test too just to make sure things are stil workin'

I need to check my wiring plug harness also , I've replaced throttle body position sensor, throttle body, mass flow sensor and still having issues with the engine power light coming on

I have heard that you shouldn't touch the butterfly valve like that because it messes with the computer and it will have to go through it's relearn process. Is that true?

thank you sir, saved me a couple $100, (loose wire in harness)

Thanks... this helps a lot.

thanks for you video ..... now im going back to my truck to see if i can fix it my selfnn

After replacing the TPS the same problem occurred again. I watched the video I did the same actions as shown and discovered it was the same exact problem with the harness.

Great stuff, thank you much.

Hi guys my partner truck just got the same issue displayed on his 2012 Chevrolet diesel 3500 . So here is what he did to get rid of the reduced engine power the check engine still there tho but need to get it reset. So what u do is drive the truck and let it pick up its speed whether is 30miles max floored or less then just put it on neutral and turn off truck and turn back on while driving so do this for a few times it should be a able to get the display removed it work for my friend . Just trying to help hope this works guys.

thanks for all the info...

have you checked the airflow sensor? right next to your air filter is a sensor, take the airbox off and look at that sensor, if the sensor is dirty or clogged that can do it! also try the tug test on the wires on the airflow sensor

Thanks Don!

hey, I have the same reduced power problem. I did what you had suggested and did the tug test at both the TB and the pedal, and cleaned the TB. I also check the mass air sensor. I have not checked the grounds yet. But i have a question. My reduced engine power displays all the time and runs like crap. If i were to take the wiring off of the TB and the truck still runs like crap, is that my problem. Just like if you were checking cylinders by takeing off the plug wires

thanks D rays

have the same issue, REP, code 1515 TPS out of range. I have checked all wires, and grounds 103 and 104. it is intermittent, started it went out wiggled EVERY wire under the hood and down by the foot pedal, cant get it to kick into REP. so I am thinking the throttlebody would be suspect and not the wires?

Do you happen to know what the name of that connector is that you're holding in your hand at 3:25 in the video? I broke the gray clip when I was removing mine and I have no idea what it's called so I can buy a new one.

I bought the throttle body sensor. Because my car was saying the same thing.' So I don't know if its the wires or the tbs. What should I do.

Great Video!

I have had a reduced engine power code for a year shuts off when engine is cold and under power at 1800 rpms and about 28 miles hour. Works when engine is warm. Summer time shuts off a few times and winter every time unless warmed up. I think I figured it out replacing the coolant temp. sensor. It has worked for the last week. Hopefully this is it.

But you didn't show us how to repair it! Great video,...gives me something to inspect and look for.

yes sir i had it happen to me took to auto zone change no 8 coil check engine light went of put newon and wires was wondering why i did not code for reduced engine power

dude, i have the same problem on my 99 camaro. aut 3.8 6cil it`s the same issue ??

my gauges go off and my locks "lock and unlock by themselves" i also get many indicators flashing is this bad wiring?

Hey Donald where would I find this on a 95 chevy malibu. that same code egine power reduce shows up on my moms car. I know I can fix it without going to the shop and being charged an arm and leg.... Help me please locate this......Thanks

Going to try that.

Do you know why my 2004 Chevy Silverado 2500 6.0 when I give it gas it doesn’t want go and it makes a pop noise to.?

ive got the same problem with a 2010 chevy I'mpala and I'm going to try this thank you

Good job! Thanks

well i thought dat did the trick.. but if anyone is still having the same trouble, there is 1 more thing 2 do.. there is a sensor on your transmission.. change that & the problem is gone..

Hey i got a 2004 silverado 1500 ls 4.8 liters and I got the reduce power on but I check the wires they look fine I clean the throttle body and still the same but I press the gas and takes forever to move to move what u thing about that I need to buy a new throttle body any ideas?