cruise control problem e320cdi

[sshamgit]

e320cdi o2year 210 000 miles ,, if traveling at over 78 miles per hour when ever cruise control is in operation after a couple of miles it drops out thats at 80 82 85 whatever speed over 78 mph,,,, anything under 78mph cruise works properly .. have changed the brake light switch with no success its still exactly the same with new switch in ,,,,,,, any ideas guys thanks in antisipation

 

[Xtractorfan]

Do a tyre check and ensure they are all the same size, and that they are a recommended size for the car, next thing to check would be tyre pressures..

 

[David Nock]

Yes, it seems to be a regular post that mismatched or incorrect tyres can cause this.

 

[sshamgit]

cruise

tyres are correct ,pressures are correct. any other ideas fellas

 

[piestore]

cruise control

Hi
Would have to agree tyre size (rolling diameter) most likly cause of problem please post tyre size on forum, Do you get any surging of speed if so this can be due to corroded rotors

 

[jberks]

if its dropping out I'd expect it to log why. Cruise will stop workng if for example a gearbox fault is detected I believe so it may be a symptom rather than the issue. Start with the codes.
Mine is dropping out randomly at the moment - any speed braking/not braking / it even trips when switched off - no real common factor - hopefully the codes will show something. I'll find out tomorrow.

 

[sshamgit]

update on my cruise problem ......last night with 4 passengers i traveled 10 miles with cruise set at 83 mph every thing was fine ....after i dropped them of tried to do return trip at same speed on cruise and just maneged under a mile and it dopped out again but it was still ok at 78 mph ....did that extra weight make some kind of differance

 

[sshamgit]

cruise problem

Hi
Would have to agree tyre size (rolling diameter) most likly cause of problem please post tyre size on forum, Do you get any surging of speed if so this can be due to corroded rotors

tyre size 215 55 16 w97 no surging

 

[jberks]

I suspect the problem is more random than that.
Mine would be fine for 2 weeks, then switch itself off instantly. Restart, 30 secs later its errored. Drive 60 miles and its fine again.
The dealer has just rung me to say that the switch appears to be the problem, yet the warning would come up without me touching it.
Best get the codes read or it will drive you mad guessing.