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Ask GM Tech (Cam) Your Own Question
GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 29520
Experience:  GM Grand Master Technician 2007. 14 years experience.
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05 dura max Allison trans in limp mode code po561 system

Customer Question

05 dura max Allison trans in limp mode code po561 system voltage how can I test the voltage any ideas?
Submitted: 1 year ago.
Category: Chevy
Expert:  GM Tech (Cam) replied 1 year ago.

Hi there, I am Cam.

Expert:  GM Tech (Cam) replied 1 year ago.

Pulling up the specifics on the code you listed, is only really for possible issues. One is very common, one is somewhat common and the other two I have yet to far the most common issue I have seen is the ignition switch. They are prone to failure with age due to build up if corrosion on the contacts inside. Just one contact pretty much dedicated to the transmission, and when that causes issues it will drop the volts and cause this code. The second most common is the transmission control module. After that it could be a wiring issue between the two or an aftermarket accessory like a remote starter or security system that is feeding off that same ignition feed. I would start by replacing the ignition switch because it is very cheap.