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Skyhammer · #3 (**permalink**) 06-14-2009, 07:36 AM

Tow/Haul Control
General

During tow/haul control, the ECM controls the engine output, transmission shift schedule and shift timing
to ensure drivability when a trailer is towed. The tow/haul control includes a throttle control, shift schedule
control, wide open throttle shift timing control and AI-SHIFT control.

The conditions required for tow/haul control to operate are as follows:
- Shift position: D position (Tow/haul control does not operate in the S position).
- TOW/HAUL pattern select switch: ON

The TOW/HAUL indicator light is used to inform the driver that tow/haul control is operating.
Throttle Control

Throttle control changes the relationship between the accelerator pedal depression angle and the throttle
valve opening angle.

During tow/haul control, the throttle valve
opening is increased by throttle control. As a

result, acceleration performance is ensured.
Shift Schedule Control

The shift schedule control changes the upshift and downshift schedules during tow/haul control.

For the upshift schedule, the upshift timing is changed to higher vehicle speeds, enhancing the use of

lower gears. As a result, drivability is ensured.

For the downshift schedule, the downshift timing is change to a wider throttle valve opening angle,
enhancing the use of higher gears. As a result, the frequency of gear changes is reduced, allowing optimal

shift quality.
Wide Open Throttle Shift Timing Control

Due to wide open throttle shift timing control, upshift timing is delayed to make use of high engine power
when the accelerator pedal is fully opened.

Wide open throttle shift control operates in 1st, 2nd and 3rd during tow/haul control.