Park brake light coming on when driving! Help please!

[alex300ce]

Hi, just wondered if anyone has had this problem or encountered it before as can't seem to find any other posts with this problem!
Got a ml270cdi 2001 w 130k on clock, couple weeks ago when stopped at the lights the park brake warning light and buzzer started. As I pulled away the car would not shift from first gear. Pulled over and switched off and on and all was good. Then couple days ago happened again but could not get it to clear by switching off and on, the only thing that seemed to cure it was about a ten min wait. It then continued to do this every 5 miles or so, if it came on whilst doing 60 or so, it would then not shift from 5th gear. Have checked brake fluid and it's ok, also the handbrake switch and that looks ok to. Any ideas on this would be a great help before I take to the garage!
Also happens now on way to work after about 10 miles always, luckily only go 11 so not to bad for last mile!
Thanks in advance!

 

[alex300ce]

Also have now seemed to notice a funny gear change just before it happens, as in a slightly lumpy change. Could I have problems with gearbox? Would that cause park light warning to come on?

 

[alex300ce]

Would a gearbox problem cause the light to come on? As I've read that the warning will only come on with the park brake switch or low brake fluid

 

[stability]

is the handbrake releasing ok ?
is the brake fluid level ok ?

if not - with the release lever pulled out - put the underside of your foot behing the pedal and pull it back - does the light go out.

failing that - get it on a star machine ESM are quite common on these - ive done a few

 

[alex300ce]

Thanks for help, yes tried that and even took the switch from bracket and had a play around with it, still the same. Think I'll have to put it on star
What is puzzling me is that every day I do the same journey and the light/alarm is coming on sooner and sooner.