Reduced engine power, weird three tone with bass, and weird electrical glitches.

[darthrevan1006]

Hello, I have a 2018 equinox AWD Lt. About 2 weeks back I started to have weird electrical glitches with dash lights going from real bright to super dark, head lights randomly turning off, and a three tone do doo dooooo sound with long bass at end coming from rear speakers and will play even when something is on radio. No check engine light at this time. On my way up north last night there was a snow storm. Now on top of all that I know have a reduced engine power message. It now starts rough. And when I go to accelerate it shoots rpm to around 4 and will stay at high rec till it hits 55 then will shift and do something till around 75 mph. I would normally put a code reader on it but I am in middle of nowhere for next 2 weeks. I had changed battery with same issue persisting

 

[Hey Vern!]

Maybe a bad ground. The reduced engine power could be related or not. maybe bad gas or moisture in the gas from the weather change.

 

[PoManNox]

Have you owned your 2018 since new?

Need more info: How many miles on it? Any aftermarket electronics on it? When exactly did you swap batteries? Does the new battery pass a load, crank and charging test with a digital tester? (can buy these for $35 online). Need to run all 3 tests for the most accurate "test".

The reduced engine power thing in the very cold can be a frozen, partially blocked charge air cooler. Just throwing some things out there, but you really need to scan for codes. One last thought, is the auto stop/start still active on it? You need to bypass that ASAP if so. It does nothing good electronically or mechanically for the vehicle.

 

[darthrevan1006]

I had it since 50k it's at 100k right now. No aftermarket anything. Just put brand new battery in it before I got up here so maybe 4-5 days ago. In UP Michigan 15 miles from nearest anything. I was thinking could be alternator. As mostly the electrical seems to be affected. Interior lights at night will be dim and then all sudden get super bright. When lights are in auto mode they will go out randomly. Have to turn light to full on to get them to stay.
And that tone is so weird. It starts off with low bass dooo then higher bass doooooook then real high bass dooooooooo. Sorry I sound stupid doing that only way to think how it sounds. And that last tone will go on for about 30 sec.

 

[darthrevan1006]

And yes auto start stop has been bypassed for the last 2 years.

 

[ricklack]

And yes auto start stop has been bypassed for the last 2 years.

Even though it is unlikely cause, I would remove the bypass adapter just to try it. Easy and can't hurt to try.

 

[ricklack]

Also if you have a battery charger or maintainer, it might be a good idea to make sure that new battery has a full charge.

 

[Moonwink]

Auto stop/start won't work if the computer isn't happy with everything it monitors. By bypassing it, you loose that feature. After I had my batteries replaced a couple years ago and the control module reprogrammed, I haven't had any problems at all. I like auto stop/start. When I works, I know all is well.