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Greg, Technician
Category: Car
Satisfied Customers: 1130
Experience:  Automotive diagnostic tech
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Have Rover 25 Automatic. If I travel over about 50mph it frequently

Customer Question

Have Rover 25 Automatic. If I travel over about 50mph it frequently (but not allways) goes into low gear at high revs.
Initial diagnostics showed error in any of 4 wires or the speed sensor. Wiring checked and sensor replaced but problem still there.
Seems to be OK for a few days after each time it has been worked on.
Couold it just be a bad connection that doesn't show in a continuity test or are there any other sensors that might need replacement?
Submitted: 5 years ago.
Category: Car
Expert:  Mike replied 5 years ago.
Hello and Welcome to justanswer..

My name is MIKE, Im happy to help / advise you on this..

What is the mileage on the car?

What is its service history like / recent repair history?

Do you have any fault lights on the dash at all or any lights flashing when this occurs?

What type of garage has done the "diagnostics" for you?

Rgds, MIKE................................
Customer: replied 5 years ago.

Age nearly 12 years

Mileage about 15000 (only did 5000 miles in first 10 years)
Always been garage maintained but nothing much needed


Current problem started about 3 months ago

Overtaking at about 60mph and engine moved to too low gear and high revs, After switching off completely and re-starting OK until reaching 50-55mph then problem recurred (but can goes for days without happening).


Yellow 'transmission' warning light comes on during problems.


Been to ex Rover garage 4 times:

1st time diagnostics showed problem in Speed sensor or in any of 4 wires.

2nd time. Wiring checked. Seemed ok afterwards for a while then recurred ... and at lower speeds (30mph) on 2 occasions.

3rd time: diagnostics again and suggested change speed sensor

4th time: changed speed sensor.

It seems to behave better for a while after each visit and then problem recurs.

Wondering if problem in wiring which is disturbed during tests. Garage suggests there may be an additional internal gearbox speed sensor.



Expert:  Mike replied 5 years ago.
Hello again Mike..

Thank you for your reply and info...

Has the transmission been flushed -and the fluid checked / changed at all??

Rgds, MIKE............................
Customer: replied 5 years ago.

Yes - this was the first thing that was done before it was sent in for diagnostics.

Expert:  Mike replied 5 years ago.
Hello again..

Thank you again for that -

Finally then has any garage done "live data" tests - as opposed to fault code checking...?

If so, what were the results of that - ?

Rgds, MIKE..................................

Customer: replied 5 years ago.

They have done fault code checking but another garage may be able to do live data tests.


I have a suspicion that the garage who put in a new speed sensor may have changed to wrong one. One goes to the speedo (the one they changed despite there being no speedo problems) and the other was connected with the specified wires directly to the ECU. I thought they were going to change the latter one.