Sensor again,

[murph]

Hi Guys,
after trying another sensor, (admittedly 2nd hand & could be faulty) still with no luck.
Checked behind the clocks, & couldn't find anything wrong there. I've got a short list of what to look at next, wanted to see what you guys think.
Thinking of replacing the kph/mph converter behind the speedo clock.
If it turns out to be 'the chip' do I need a new set of clocks?
Other things to look at would be the other sensor located in the gearbox. The ECU unit, or any of the solenoids?
please

[murph]

Bump,(sorry) anyone?

[TonyN]

take out the chip, and how it goes. it could be the speedo itself

when you short out the diagnostics box and press the O/D button, do you get any fault codes?

[murph]

TonyN,
when the speedo started playing up, the O/D light has never lit up, unlike some of the threads I read here.
I haven't done a diagnostic myself, but gave it to the garage on my signature & he came back with a code of '42'.
The information conflicted I think as he said the fault was something to do with the brakes.
I tried to source a sensor, which I ended getting one 2nd hand. Thats been swapped over but still no joy.
How do I go about checking the diaognostic myself?
Thanks for your time & help.