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My 98 Toyota Spacio often changes down a gear when I touch the brake going downhill. I presume this is a clever design to enhance safety but a modern car usually does not need to change down and it just wastes petrol. Can the auto computer be modified to get rid of this annoying feature?

Stuart

From the "Ask Jack" archives - 14 December 2009

If I am correct this car is fitted with a manual overdrive button on the gear lever which, when operated allows the transmission to either change into the overdrive mode or holds the transmission in third gear.

What I believe you are experiencing is the transmission control unit reacting to the engine throttle position, vehicle speed and the pedal brake application.

When a pre-set programme is reached within the transmission control unit, the transmission is automatically making the change into third gear by overriding the overdrive button.

Unfortunately this cannot be changed or adjusted.

In some situations this design would be a blessing to have, in others a frustration such as you are experiencing.