GMC savana 2500 stop from running

[Cortazac]

Hello, everyone
I will like some suggestions. I was driving my gmc which I recently change the transmission.
My dashboard where not working and I was going on 65. All the sudden it drop to 55 than to 45 and finally it stop. Try to turn it didn’t want to start. Towed it to a shop and the machine read codes P0758, P0300, P0101. Any assistance will be helpful. Thanks

 

[Maverick6587]

Welcome to GMTNation!

I know you took your vehicle to a shop but, do you have an OBDII code scanner to use or one that you could borrow? I assume you still cannot start the vehicle. Does it try to start at all or just cranks and no firing sounds at all? Let us know what happens when you try and start it now, please.

P0758 is the computer not seeing an RPM change for the shift in gears from 2nd to 3rd gear.

P0300 is a random misfire.
Have you noticed any misfires or engine shaking before your transmission issue? Is this the first time you've seen a P03***?
It might take a few time driving it but you should get a specific code for which cylinders are actually misfiring.

I would inspect your spark plugs and if they look black, replace them. Only replace the spark plugs with ACDelco plugs.

P0101 is a problem with the readings that the Mass Air Flow sensor is sending to the computer.

Have you done anything to the vehicle besides replacing the transmission and did you replace it yourself or have a shop replace the transmission?

 

[Mooseman]

Thread moved to proper section.