Tow/Haul Mode Description And Operation

WARNING: This page is about a different car, the 2018 GMC Yukon XL, 2018 GMC Yukon, 2018 Chevrolet Tahoe, 2018 Cadillac Escalade ESV, and 2018 Cadillac Escalade. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Tow/Haul Mode

Courtesy of GENERAL MOTORS COMPANY

The Tow/Haul Mode adjusts the transmission shift pattern to reduce shift cycling. This provides increased performance, vehicle control, and enhanced transmission and engine cooling when driving down steep hills or mountain grades, towing, or hauling heavy loads.

The selector button is on the end of the shift lever. Turn the Tow/Haul Mode on and off by pressing the button. When the Tow/Haul Mode is enabled, a light on the instrument cluster will come on.

When tow/haul mode is selected, the tow/haul switch input signal to the body control module (BCM) is momentarily switched from 12 volts to zero volts. The BCM then sends a signal out on the serial data line to the transmission control module (TCM) to increase transmission line pressure and extend the time between upshifts. Selecting the tow/haul switch again disables tow/haul mode and returns the transmission to a normal shift pattern.