I dragged the X300 out of it's cocoon on Sunday and brought it to work on Monday. Much of my trip is heavily patrolled 25 MPH residential areas, so I find it best to just use the cruise control to best "observe" my speed. Monday it worked fine - both, to and form work.

However this morning, no luck. The car didn't even think about registering a base speed when I tried to set it. Yes, I did bring the main switch toward me, and the light was on.

Any ideas where I should start to diagnose the intermittent fault? Does the speed control have anything to do with the ABS/TRAC operations? By this I mean, if there's a fault that causes my Traction Control to engage, whereas I turn it off to drive normally - would that have an affect on the Speed Control?

 

From memory, I believe if your ABS isn't working, you won't have cruise control either. This is one of the ways to help determine if you are getting a "false" ABS warning light on your dash. You might have a suspect ABS wheel speed sensor, but your ABS is still working. If however, your module or pump is inoperative, you wont necessarily have ABS and if so, neither will you have cruise control.

FWIW I always thought cruise only operated at speeds of 40MPH and above. I have never ha cause to use mine at low speeds. Usually just on dual carriageways (60mph) and motorways (75 mph)

Others may update or expand.

 

well, it worked perfectly on the way home from work yesterday. Used it at 30 MPH, just fine. So, I'll assume it's just possessed by the devil.

 

Interesting............. Those intermittent gremlins are always the hardest to nail down. I must check and see what's the slowest speed that my cruise will operate at.

 

I think the lower limit for Cruise is 25mph.

 

Well, here's an added twist. The "Trac Fall" light came on this morning... and the speed control worked.

Looks like some soldering is in my future.

 

I'm pretty sure the lowest speed is 30mph tbh.

 

I have a bluetooth OBDII reader in the car (leave it there so I don't misplace it). It reads the car's speed from the ECU, so, I'll test it to see how low it will go on the way home. Not much traffic today.