does tow/haul=overdrive

[shotgun]

Based on the manual, there doesn't appear to be a way to disable OD without limiting the transmission to 3rd, 2nd, or 1st.

D (Overdrive) with Tow/Haul On
The Tow/Haul feature improves transmission operation when towing a trailer or a heavy load. All transmission gear ranges are available when using Tow/Haul.
Tow/Haul can be activated by pressing the transmission control switch on the end of the gearshift lever (column-shift transmission) or on the side of the gearshift lever (floor-shift transmission).

Tow/Haul delays upshifts to reduce frequency of transmission shifting. Tow/Haul also provides engine braking in all forward gears when the transmission is in the D(Overdrive) position; this engine braking will slow the vehicle and assist the driver in controlling the vehicle when descending a grade.

3 (Third)
Transmission operates in third gear only.
Used for improved traction on slippery roads. Selecting 3 (Third) provides engine braking.
2 (Second)
Transmission operates in 2nd gear only.
Use 2 (Second) to start-up on slippery roads or to provide additional engine braking on downgrades.
1 (First)

Transmission operates in 1st gear only.

Provides maximum engine braking.

Allows upshifts by moving gearshift lever.

Will not downshift into 1 (First) at high speeds; allows for 1 (First) when vehicle reaches slower speeds.