Originally Posted By: Doog
Originally Posted By: donnyj08
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The Edge AWD is super picky. If any of the tires are worn uneven, or mismatched the "PTU" will go bad. It is a super weak form of AWD transfer case.
No the cause is the diameter of a mismatched tire set (L to R side) causes each wheel speed sensor to report a differen amount of revolutions to the ECM. So the ECM thinks the wheel with the higher count is slipping and turns on the AWD. Then when the vehicle comes to a stop or the driver steps on the brake it shuts off. Then when the driver accelerates it turns on again...over and over and over until it wears out the actuator clutches after 2-300,000 cycles. Which would under normal cycles be about 200,000+ miles or 15 years of driving.
If you read the owners manual it will clearly tell you to replace F&R tires in sets.
Most GM transfer cases that have an "AUTO 4WD" setting will do the same thing
Chev's auto 4wd and their awd system are different in more ways than similar so your comparison isn't accurate.
The auto 4wd runs in rwd til IT senses slip then engages the front tires. The awd system is always engaged and transfers 62% of power to the rear and 38% to the front at all times.
The 2 systems aren't the same and aren't similar in their engagement. Having owned 3 trucks,one of each system I am intimately aware of each.