I’m new to this forum and coming here as a last resort effort to get more opinions on what the issue is with my 2018 Traverse RS is. I have an idea on what the issue is, but a second opinion would help solidify my theory. For starters I will express the issue is INTERMITTENT happening a couple of times every few weeks to a week apart.
1) Reduced Engine Power warning with light.
2) Assisted Steering Power reduced warning with light.
3) Service Parking Brake warning with light.
All three pop at the same time typically while driving, but recently it is happening when I first turn the car on. I am able to cycle the engine, turning it on and off about 5-7times before all the warnings go away. However, after cycling the engine I am left with only the Assisted Steering Power reduced with the check engine light still on.
Here is where is gets more complicated… in between this intermittent issue when no service warnings or lights have been popping, my RPM’s are way higher than what it should be. Typically accelerates/ shifts gears between 1,000-2,500rpm. Now my car gets to 3,000-5,000rpms in order to shift depending on how fast I am trying to accelerate. I was testing that issue out and with the gas pedal all the way down and had to let off because it began to go into the red.
This lead me to start looking at the battery voltage. First time starting up the engine it is about 13v, and once I begin to accelerate and start driving it drops down to 12.5-12.7v. While the car goes into limp mode and I have all the warnings and service lights on, the voltage consistently stays at 14v.
I am still having all of these issues even after the dealership said it was a high pressure fuel pump (which they replaced twice, because the second time they replaced it was because they didn’t want to look into what I said could potentially be wrong and wanted to rule out it just being a bad part…)
I then replaced the battery because it was bad, but voltage output was still the same issue. I looked into the alternator and when tested it was putting out 12v.
so then I replaced the alternator… still having all the same issues listed above still. I have checked the connectors too and from alternator as well as wires, all checked good. Tested the ground for the battery, checked good. All fuses were good and nothing blown in the fuse box. Checked all connectors and wires from the ECM(ECU,PDU… whatever you want to call it) all checked good.
my hunch is the ECM is is bad and needs replaced. The second time I took it into the dealer they refused to look into it and are still refusing to looked into it. They only wanted to check the wiring harness that comes from the fuel pump and that is it. I have taken it to 2 mom and pop shops and they both diagnosed it as the ECM however the dealership has to replace it and they won’t for whatever reason. My question is what do yall think… ECM? Or potentially something different?
** there is a recall out for the 2018 Traverses 2.0L for the ECM being bad, but mine is the 3.6L. Could it potentially be the same recall but for the 3.6?
I will attach a list of codes (ignore the tire pressure sensor codes)
