Diagnostics Results

[StuS]

Just had my 98 SE in for diagnostics on the auto gearbox. Came back with faults on the "Road Speed Sensor" and the "Torgve converter lock-up clutch".

The guy at the gearbox specialists was sucking his teeth and muttering about high costs to repair given the age of the car...

Any thoughts from some of the experts on here before I start making any decisions?

Thanks

[cazyp]

What symptoms do you have if any?

Re the Torque converter lock-up clutch it is worth draining and replacing the auto transmission fluid and change the filter. Make sure you refill with the correct fluid for your box. This often clears the fault code.

(If you're interested The torque converter monitor (tcm) monitors both engine rpm & Turbine rpm. The torque convertor clutch locks the two torque convertor halves together causing them to spin as one. If the rpm of one is out then you get this code.

The main housing is driven by the engine flywheel/flexplate, the other half (turbine) rotates freely inside the torque convertor and is the output to the transmission.)

There is a torque convertor soliniod on the gearbox. Might have failed? Worth a try assuming you have driving issues and you have tried the drain/filter/refill.

Re 'Road Speed Sensor' I'm guessing one of your ABS wheel road speed sensors, also called road speed sensors. A diagnositc will show up which wheel the fault is on.

[StuS]

That's exactly what I'm worried about - I don't want to start spending a small fortune on repairs if a simple drain down & filter change may solve the issue...I just got the feeling that they weren't too interested due to the age of the car and were just trying to get me to either spend large amounts of money or bin the car...

Thanks for the advice, I'll give this a try first...

[cazyp]

Well worth a try. What is the problem/s with the box?
BTW I had to drain/refill twice on my old BMW 540 before it cleared.

[StuS]

Somedays it's fine, but on others, it either doesn't reach 4th gear. Other days it's running in 4th and suddenly drops down into 3rd and sticks in 3rd...There's no big clunky drops when it drops out of 4th, it just drops down as if it was a manual change...

I'll give the fluid change a go and see what happens...it's a cheaper alternative to start with anyway!!!

[cazyp]

Did you get anywhere with this?

[StuS]

Got a 2nd opinion done - took it to another auto transmission specialist. They took it for a drive and from that diagnosed a valve pressure issue. According to the mechanic, it was not possible that there was a problem with the torque converter as this would put the car into "get me home" mode.

They stuck it back on the diagnostics machine and cleared the faults - and took it out again - and so far the issue hasn't flared up again...

Their feeling is that it's probable the sensor issue that's causing the problem as it's changing fine all the way to 3rd gear but having an issue with 4th.

Anyway, so far the cost has been minimal and it looks as if it won't be a death sentence for the gearbox!