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Ask Gm Tech (Cam) Your Own Question
Gm Tech (Cam)
Gm Tech (Cam), GMC Mechanic
Category: GMC
Satisfied Customers: 29534
Experience:  GM Grand Master Technician 2007. 14 year experience.
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I have a 2003 GMC Sierra duramax lb7 Recently idling rough

Customer Question

Hi I have a 2003 GMC Sierra duramax lb7
Recently idling rough and I put the scanner
And I got these codes UNK B2961 and
hVAV B0229 trying to find out what wrong with it
Submitted: 1 year ago.
Category: GMC
Expert:  Gm Tech (Cam) replied 1 year ago.

hi there, I am Cam, Can I get your first name please?

With your truck, does smoke at idle? How does it run off idle?

I think those codes are not related. B2961 is the key in cylinder alarm. "
B0229 is recirc actuator issue. So this is strictly a fuel injector issue.

Customer: replied 1 year ago.
It runs good off of idle ,it's just when I'm slowing down or stop that makes a weird noise
Is there a way to find out about the injectors being bad?
Also the engine light was on them it came off and the truck stop doing what it was doing before by either way
Before the idle will move a little at times when I'm stop or not going
Customer: replied 1 year ago.
My name is Derbis
Customer: replied 1 year ago.
The truck doesn't smoke at idle
Expert:  Gm Tech (Cam) replied 1 year ago.

Derbis, so we can see what each injector is doing off idle. We are looking at the balancing rates. These are changes each injector makes by the computer to keep it idling smooth. With a scanner we look for the balancing rate for each, at idle hot the spec is between -4 and +4, and in drive, -6 to +6. Any outside of that spec need to be replaced. Can you do this?

Customer: replied 1 year ago.
Actually I can't I do not have the type of scanner that I would need to find out I only have an efi live
Expert:  Gm Tech (Cam) replied 1 year ago.

EFI live may be enough to do that.

Customer: replied 1 year ago.
How can I do it?
Expert:  Gm Tech (Cam) replied 1 year ago.

Oh, I thought you had EFI live. WE need to have that type scanner to see that data. There is no way around it.