Wrench Light?

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Nov 21, 2014 | 08:10 AM

#16

2006White60

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Tuned

Joined: Mar 2014

Posts: 452

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From: Cheyenne Wy.

If it means anything I had the Tow/Haul switch on and there was a 30-40 MPH 3/4 to the right headwind.

Nov 21, 2014 | 08:31 AM

#17

MC5C

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Joined: Jun 2012

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In a normal situation with a working VGT system the turbo will be able to control the boost by changing the vanes in response to PCM commands. You'll never get a wrench light no matter what you do, you can tow up hills to your hearts content. When the turbo seizes the vanes stick on one position. The vgt solenoid can't move them to control boost so boost is developed in response to exhaust gas flow. What happens is as soon as you downshift the engine speeds up and gas flow increases a lot almost instantly. When you are in Tow/Haul mode the downshift is commanded earlier so you get the increased power earlier and the engine is spinning faster so EGT's are kept lower. All good things, but the turbo boost spikes earlier and it's harder to keep the boost low with your foot. With a stuck turbo you need to drive by the boost gauge if you are towing a load.

Brian