K11 Automatic gearbox

[CMF_Cat_N]

I own a 1995 Nissan Micra with an automatic gearbox.

The gearbox has suddenly started to refuse to change up when the speed of the car increases. As a result, the car is stuck in "first gear", unable to go faster than about 18mph.

Transmission fluid is fine and I've done the N-CVT diagnostic check and no fault is found.

Has anyone experienced this problem or can anyone suggest a possible fix?

Thanks!

 

[CMF_david (2)]

have u checked the carbon brushes? Otherwise i have nothing

 

[CMF_Cat_N]

Thanks for the tip but yes, checked the carbon brushes and they were fine. Resistence was 2.5ohms (normal)

Also tried changing the speed sensor to no effect.

May have to admit defeat :-(