Dreaded reduced power mode. argggggggggg

[Eldiablo]

Okay I have an 05 tahoe 315,000 miles. Just got the reduced engine power message. So I am going through all that I have read. On the back of the motor I have the ground on the driver side that goes with the silver one. I beleive its for the ac compressor. On the pasenger side I have nothing. I need to know what is suposed to be grounded there so I can hunt it down. So far I have put a new throttle body, change the the throttle computer. Did the ground improvement but still get this thing. My battery while its running does not go below 14.6 12.4 when its turned off. 55 lbs fuel pressure. I am beating my head. I put new injectors, gaskets, this is driving me crazy. And its the old ladys tahoe, and she is driving my truck. She is ******* vehicles. This thing has been bullet proof for so long. I mean has the original transmission in it. Hlep please??????????????????????????????????????????????????????

Ryan

also I really could use a schematic showing me what grounds go where and what they are attacked to???

 

[Fless]

Post up the codes you're getting; that might help us help you.

I've attached a grounds diagram from the uptfitter's guide.

 

[Eldiablo]

typical 1516 code I beleive

 

[Eldiablo]

Post up the codes you're getting; that might help us help you.

I've attached a grounds diagram from the uptfitter's guide.

Thank you. One thing that is new. Last night early this morning, when I started it , idled perfect, but right berfore is went crazy, I could hear loud clicking sound, seems like coming from throttle body?

 

[Fless]

Moved you here from the 2021+ section.

 

[Fless]

Based on your stated P1516: with a good scanner compare the throttle position with the pedal position values. There are some good YouTube videos on how to do that.

Also, the wiring from the throttle body has a tendency to break under the wiring insulation. Very carefully inspect the wiring harness from the throttle body back about 6 or 8", looking (feeling) for wire that's compromised under the insulation. You can get a new pigtail for that harness, or repair broken wiring.

 

[strutaeng]

Pop the fuseblock cover and unclip to inspect the terminals/connectors that plug to the actual fuseblock. It's very easy to do this, you'll just have to remove the little corner brace. Have a wiring diagram to pinpoint the wires that go to the throttle body.

Maybe you have corrosion there?

 

[blackelky]

You guys are giving me hope with these high mileage posts...ever had a trans replacement ?

 

[Eldiablo]

Based on your stated P1516: with a good scanner compare the throttle position with the pedal position values. There are some good YouTube videos on how to do that.

Also, the wiring from the throttle body has a tendency to break under the wiring insulation. Very carefully inspect the wiring harness from the throttle body back about 6 or 8", looking (feeling) for wire that's compromised under the insulation. You can get a new pigtail for that harness, or repair broken wiring.

Did I mention I sold tools for 34 years. I have been wanting to get and x tool d7. Havent done it yet, I sure could use it.

 

[Eldiablo]

Did I mention I sold tools for 34 years. I have been wanting to get and x tool d7. Havent done it yet, I sure could use it.

Brand new pig tail. Ive had the harness under the hood completelly apart.

 

[Eldiablo]

You guys are giving me hope with these high mileage posts...ever had a trans replacement ?

Nope all original. If it goes out, I can do it myself. 4l60 and 4l80 basically a turbo 400 with overdrive.

 

[Eldiablo]

Pop the fuseblock cover and unclip to inspect the terminals/connectors that plug to the actual fuseblock. It's very easy to do this, you'll just have to remove the little corner brace. Have a wiring diagram to pinpoint the wires that go to the throttle body.

Maybe you have corrosion there?

I have not been able to locate a wiring schematic for this tahoe? The boss man gave me a ground schematic.

 

[Eldiablo]

Based on your stated P1516: with a good scanner compare the throttle position with the pedal position values. There are some good YouTube videos on how to do that.

Also, the wiring from the throttle body has a tendency to break under the wiring insulation. Very carefully inspect the wiring harness from the throttle body back about 6 or 8", looking (feeling) for wire that's compromised under the insulation. You can get a new pigtail for that harness, or repair broken wiring.

By the way I was just checking my b pillar. The only grounds I have there are on a bolt with nut, two wires. Looks fine, but I noticed I had replaced the connector to the blower, and the connectors are all burned up, and the wires got so hot it melted the loom and melted two wires together. I solder everything now. Learned my lesson driving a diesel tool truck. Could this be it?

 

[Eldiablo]

Pop the fuseblock cover and unclip to inspect the terminals/connectors that plug to the actual fuseblock. It's very easy to do this, you'll just have to remove the little corner brace. Have a wiring diagram to pinpoint the wires that go to the throttle body.

Maybe you have corrosion there?

about a month ago I took all the fuseblock apart and cleaned it all with purple cleaner and a wire brush got it crystal clean. Blew it all out, sat it out in the son for a week. Looks new. I also took apart every connector cleaned them out and wd40 them. If I can get a wiring schematic, I can ohm test all of the wires. I have done alot of that already. They all were at the 1650 range. I personally think I need to replace the pedal sensor. Also, last night I found all the wires going to the blower assembly fried. I cut out all the connectors and soldered them up. Just waiting on all new injector pigtails, should have them wednsday so I can fire her up and pray.

 

[stretchit]

Any update? im having the same issue. bought to start cutting every wire and putting in new wires. What a dum problem to have. Put 10k into a rebuild just to lose TB signal lolol wtf man. Tuner even reved it up before the tune then it just loses signal hahahahaahah I'm losing my mind