Gearbox Fault

[blackpoolbobbie@btinternet.com]

:( hi i have an auto previa that changes gear at speed on its own when it is warm does any one out there know what the problem with the auto box may be thanks

[blobstrom]

:( hi i have an auto previa that changes gear at speed on its own when it is warm does any one out there know what the problem with the auto box may be thanks

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Could be a number of things, there are 3 solonoids in the gearbox which are controlled by the engine ECU, I own a Lucida diesel but the gearbox is basically the same i think.

The ECU decides also by engine temp whether to engage Torque converter lock-up. Check all your connections is a start and also maybe give more detail on what the gearbox is doing (changing from 4th to 3rd for no reason etc..)

Because it maybe a vacuum pipe split etc..

[blackpoolbobbie@btinternet.com]

:( hi i have an auto previa that changes gear at speed on its own when it is warm does any one out there know what the problem with the auto box may be thanks

←

Could be a number of things, there are 3 solonoids in the gearbox which are controlled by the engine ECU, I own a Lucida diesel but the gearbox is basically the same i think.

The ECU decides also by engine temp whether to engage Torque converter lock-up. Check all your connections is a start and also maybe give more detail on what the gearbox is doing (changing from 4th to 3rd for no reason etc..)

Because it maybe a vacuum pipe split etc..

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thanks the auto gearbox changes up but slowly when its warm