Check Engine light 3.0L Duramax

Dave Cochrane · July 18, 2020

The check engine light on my 2020 3.0L Duramax came on and stayed on. The fan seems to run instantly even when first initially started. Has anyone seen this?

i called onstar and they didn’t help much. Two codes a P20F8 and a P200A. They told me to get it into dealer. Only issue is dealer not open till Monday. We wanted to tow the boat today but it is suggested to not use for hauling or towing

Ojustracing · July 19, 2020

DTC P200A

Intake Manifold Runner Control Valve Performance

DTC P20F8

Intake Manifold Runner Control Valve Control Circuit Performance

Reduced Engine Power = Active
P16 Instrument Cluster = Reduced Engine Power
Warning Message = Service Emission System /Service Exhaust Fluid System

caspertek · July 26, 2020

Any update on this? My truck threw P20F8 this morning.

Colossus · July 27, 2020

8 hours ago, caspertek said:

Any update on this? My truck threw P20F8 this morning.

Did you catch it and throw it back?

Dave Cochrane · July 27, 2020

19 hours ago, caspertek said:

Any update on this? My truck threw P20F8 this morning.

Yes I had truck to dealer last week. They told me the intake control valve needs to be replaced. They had to order it in and closest place to get was in the USA and said it may take two weeks to get

Were you able to get yours into dealer? Be interested to see if yours is the same

Edited July 27, 2020 by Dave Cochrane

caspertek · July 27, 2020

40 minutes ago, Dave Cochrane said:

Yes I had truck to dealer last week. They told me the intake control valve needs to be replaced. They had to order it in and closest place to get was in the USA and said it may take two weeks to get

Were you able to get yours into dealer? Be interested to see if yours is the same

I dropped it off at the dealership this morning but no word yet.

Maniac88 · August 18, 2020

what was the outcome of this? Had same codes and dealer informed me they will be replacing the intake manifold.

thanks!

Dave Cochrane · August 19, 2020

Yes that’s exactly what they ended up replacing on mine. It took a day and a half

have had the truck now for a few weeks and has been good.

Frederic Emard · September 9, 2020

I have a 2020 GMC Sierra 1500 with the 3.0 Duramax and also having the check engine light coming ON and OFF. Appeared first time at about 4500 miles and cleared by itself. Returned again at 5500 miles and cleared by itself again. Brought it to a dealer and they found history DTCS P200A Intake manifold runner control valve performance and P20F8 Intake manifold runner control circuit performance. The codes again reappeared at about 6500 miles and again disapeared by itself. I used my BlueDriver code reader today and it's showing 1 Confirmed Trouble Code : P20F8 (Intake Manifold Runner Control Circuit Performance Bank 1). Somehting's wrong!!