Tow Haul
Just wondering when to use Tow Haul? I know down hill is the best but any thoughts on the flat or uphill or just all the time?
Forum Discussion
Not all tow/haul modes are created equal.Some just change shift timing, while others are more complex.
The Tundra has a more complex tow/haul mode.
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).
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.
Powertrain Cooperative Control
Through cooperative control with ETCS-i (Electronic Throttle Control System-intelligent) and ESA
(Electronic Spark Advance), and electronic control of the engagement and release speed of the clutch and
brake hydraulic pressures, excellent response and shift shock reduction have been achieved.
Also, On my Ford, no tow/haul mode means no exhaust brake.
The Tundra has a more complex tow/haul mode.
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).
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.
Powertrain Cooperative Control
Through cooperative control with ETCS-i (Electronic Throttle Control System-intelligent) and ESA
(Electronic Spark Advance), and electronic control of the engagement and release speed of the clutch and
brake hydraulic pressures, excellent response and shift shock reduction have been achieved.
Also, On my Ford, no tow/haul mode means no exhaust brake.
