Chev 6L low power warning light?

[roadbiker1]

My 2007 Chev 6L now occasionally shows the "low power" warning light in the upper Left of the panel on startup, usually extinguishes after a minute. Owner's manual doesn't say what triggers it... oil level and pressure show good, temp in bounds, voltage seems ok. Didn't use to do this, engine now has about 80k on it. Any ideas? thanks

[booster]

Originally Posted by roadbiker1

My 2007 Chev 6L now occasionally shows the "low power" warning light in the upper Left of the panel on startup, usually extinguishes after a minute. Owner's manual doesn't say what triggers it... oil level and pressure show good, temp in bounds, voltage seems ok. Didn't use to do this, engine now has about 80k on it. Any ideas? thanks

It can be a lot of things and the triggers have changed over the years, AFAIK. Best to check to see if it is setting any engine fault codes first with a code reader or many auto parts stores do it for free.


You may need to get it to a diagnostic shop to have them look at the sensors in real time when the light comes on to really know for sure. Most likely a sensor or dirty throttle body, I think, if you have the drive by wire which fazed in for 2007. You can tell easily if you have it by looking to see if you have a throttle cable or not. The pedal sensors seem to come up a lot in a search of the reduced power mode kicking in. Don't be surprised if it turns out to be a loose or bad connector or wire in those same circuits, and it can be even harder to find.



https://www.carparts.com/blog/what-t...-engine-power/

[SteveJ]

Our '07 Buick had an intermittent low power issue. I researched a bit and found that the throttle pedal position sensor connection could be an issue. The car was out of emissions warranty but GM covered installing a new entire sensor assembly. The dealer did shotgun some parts at it. The $$$ on that stuff does add up quickly. The bill was over two grand.

[rowiebowie]

Originally Posted by roadbiker1

My 2007 Chev 6L now occasionally shows the "low power" warning light in the upper Left of the panel on startup, usually extinguishes after a minute. Owner's manual doesn't say what triggers it... oil level and pressure show good, temp in bounds, voltage seems ok. Didn't use to do this, engine now has about 80k on it. Any ideas? thanks

I had an episode last Fall with my '2011 Chev 6L. The dash showed "reduced power" (or could have said low power) plus a variety of other seemingly unrelated messages. Lights were going off like Christmas. Ultimately the OBD code showed "p1682" (which as usual, was really no help at all). At first the problem could be reset by stopping and restarting the engine. But it happened more frequently until the engine shut down completely and would not start after driing appromiately 20 miles after the first instance.

Turns out it was one of 5 similar fuses in the box under the hood. I'm pulling what little hair out that I have left because I can't find the spare I bought and provide you with the fuse # and part #. I will look some more later, but no promises.

However, my van was towed to a Chevy dealer and their service department diagnosed as "Poor connection at fuse block to ignition powertrain". He merely added some dialectric lubricant and test drove it thinking the problem was solved. It wasn't.

We started a trip and were 300 miles away when the scenario repeated itself and the van stalled by the side of the road between towns. Luckily, I was able to call the service department and they connected me to the technician who told me what fuse it was. Earlier, while on hold, I had researched the owners manual and determined the engine fuse block had 5 indentical fuses, one of which was for the dash a/c.

I was able to pull the faulty engine powertrain fuse and swap it with my a/c fuse. Immediate results were that the van started fine and I no longer had a/c which confirmed a bad fuse (also referred to as a relay by the technician). At the next town I stopped at an Autozone and picked up a replacement and a spare fuse. We continued the next 5,000 miles and still no recurrence of the problem to this day.

In summary, the Chevy tech was negligent in not replacing the fuse as a precaution at the time of my service visit as it was the fuse (not it's connection in the engine fuse block) that was at fault.

[mkguitar]

very generally


carry spare fuses


you can buy fuses on which an LED lights if they blow- easy to find the culprit ( but not any fault)
many chevys also have a fuse block under the seat



"most" electronic problems are caused by a poor connection, often simply unplugging, then replugging the connection renews the contacts


dieelectric grease is not conductive, it can insulate, it may also trap moisture into a connection allowing corrosion- it's a double edged sword.




every few years, I remove each fuse, brighten the leg with scotchbrite pad and use a little deoxit on the fuse block.
I will do same for connectors I can easily get to, for recessed pins I use a fiberglass "pen" which is often used to clean nicks in paint before touch up "nic sand"


I do have a code reader/ reset app on my phone ( obdfusion) which I use with a $20 dongle*


on start up, many sensors are not yet active- waiting for temperatures to settle ( o2 sensors for one)


I did see a low power warning once on our van while driving ( up steep grade, very hot, kicked down to 2nd- ) and code reader told me if was the MAF sensor
Reset, was fine for the 400 miles home
then I cleaned the sensor- been fine since, just an anomaly, but cleaning sensor is easy and I had to do the air filter anyway


for all the "trouble" - the stuff we can't see and mystery codes and warning lights, these motors make terrific reliable power with great fuel economy and low emissions






mike





*I had a rental car throw a code and "brick" itself 40 miles from town- I had my dongle, so reset and was able to return it

[booster]

The part that Rowie was mentioning, I think are the relay which are much larger than the small fuses and do fail if have bad connections. I probably should through a couple in the tool bag also as it is pretty common. I don't think this is the OP's issue, but you never know.


IMO, and also all the connector manufacturer's opinion, is that the idea that dielectric grease, or other "connector" grease in push connections, is bad because it is an insulator is pure Urban Legend. Again my opinion, is that getting grease in over the contacts enough to sealing them from air that will oxidize them and water that will corrode them, is one of the best things you can do for almost all connections. Most connectors I have seen lately already have grease in them from the builders of the equipment. The "grease is bad" thing is all over the internet lately but as with all things like this it is best to go to the experts and the manufacturers to see what they say about it. I greased every connector I disconnected on my 96 Buick when I had the entire running gear out of the car, and when I put it back together I could see the sensor readings at the PCM on the Tech 2 diagnostic meter and all where spot on to what they should be.