jerryml430

hello everyone
so about a 2 weeks ago the check engine light came on the car and once i turn the car off the check engine light will go off which is happened couples of times during a week so took the car to the shop i usaullay go to and they said it's the crank sensor so i got that replaced and they never clear the code. i was driving the car yesterday and going up to the mountain and once i was making it my way back down the check engine light came back on, turn the car off after an hour the light were gone been driving almost all day today and the light never came back on. do you guys think that happened cuze they never clear the code or there is something else is going on? i'm taking the car back to the shop in couple days since i don't have time but would like to hear from you guys it thats ever happened with you

phister

i would take it to an autoparts store and have it read when it comes back on again to make sure its the correct code for the crank sensor. If the crank sensor was going back youd start to have problems with the car turning over when trying to start it. Just turning the car on and off to clear it isnt such a good idea. If the car is running fine when the CEL comes on just drive it to the closest autoparts store and have them read the code so they can tell you the issue.

Most CEL are stored until its been cleared. Have it cleared after figuring out the issue and if it comes back on youll know thats really the issue and have it replaced.

SunnyRayToronto

Technically, when replacing CPS, it should be recalibrated using MB STAR Diagnostic System. But it seem it can recalibrate itself over time,.... or you can try to help it recalibrate by putting it in 3rd then half throttle to 4K rpm,... do this twice.

jerryml430

thanks for the info i'll drive it back tomorrow to the same place and see if the light will come back or no. you know i was not trying to clear it by turning of the car but that happened at night and all autoparts were closed already then i went home o i turn the car off then i left again to buy something and at that time the light was gone

jerryml430

thanks for the info, i'll try that tomorrow before i dive it up to the same place and see what will happen, it's really strange that the cel come on only when i drive up to the hill or down but driving in the city never cuze that

SunnyRayToronto

So did it work?

If you had NO cps faults prior to change then no recalibration needed.

If you had cps faults,... ideally STAR to recalibrate. Or in PARK, rev slowly up to 2500RPM in 2 minute,.... then hold at 2500RPM for 30 seconds; then drive,.... that should recalibrate the CPS.

johnand

I have a STAR system and never bothered to calibrate the CPS after replacement and never had an issue. I would drive it for a while Jerry and see if the CEL goes away on it's own.

SunnyRayToronto

Well,.... then you got lucky.

But according to Mercedes,.... whenever the CPS gets changed it MUST be recalibrated. The best way to recalibrate the CPS is using STAR. The method I specified is more of a hack then a sure thing,... it forces the car to recalibrate it itself.

Anyways,.... whether you recalibrate or not is really up to you,.... if not then, there's a higher probability that it will still randomly stall or randomly not start at all,.... as a poster recently said,... a car with a faulty CPS is like a women on menopause,..... Personally, I wouldn't mess with a women on menopause. So are ya still feeling lucky?

C230 Sport Coup

Maybe they didn't replace it.