Bluebird tsfe eng wrng light comes on

[I’m old greg]

Ok.
So I bought the bus popped some new batteries in and jumped on the road.when I turn the ignition to warm up the plugs there’s a buzzing sound and the eng wrng light on the dash lights up.
This stops after a few seconds.
Every now and then it will come on while I’m driving especially when I’m idling at a stop light.
Generally it goes away once I give some throttle to the engine.
Any advice is appreciated.
Brand new to the site excited for this new adventure.

 

[2kool4skool]

I see by earlier posts you've got a 5.9 Cummins, what year? Sounds like SES light? If so it could be as simple as low volts. I get a SES occasionally and my Scan gauge D shows low volts.
I assume your engine does not have less power when this happens (de-rate)?