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eautosales, ASE MECHANIC
Category: Mercedes
Satisfied Customers: 15040
Experience:  ase certified
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I have a 2005 c230. The temp sensor was repaired and the computer

Customer Question

I have a 2005 c230. The temp sensor was repaired and the computer reset to correct the fault. after 2 weeks it was not ready for a CA smog test. It is still not ready after another 2 weeks. The monitor says that all of the functions are ready with the exception of the catalytic monitor. My mechanic how specializes in german cars used his analyzer to check all the codes (OBDC & Mercedes) and there are no failures. Just the Cat monitor show not ready. What do I do?
Submitted: 6 months ago.
Category: Mercedes
Expert:  eautosales replied 6 months ago.
how many miles since reset?
Customer: replied 6 months ago.
over 100
Customer: replied 6 months ago.
are you there?
Expert:  eautosales replied 6 months ago.
the only way to set a readiness monitor is to drive it...sometimes it takes a few hundred miles
Expert:  eautosales replied 6 months ago.
have you done ant hi way driving and a mix of stop n go?
Customer: replied 6 months ago.
This not an answer. It has been at least 4 weeks and there are several comments on the internet about this being an issue and never resetting. Do you have any knowledge about when just driving does not reset one function?
Expert:  eautosales replied 6 months ago.
it is the only other reason is pending codes if there is a pending code a readiness monitor wont set... but 100 miles is not always enough for a drive cycle
Customer: replied 6 months ago.
Yes I have been on the freeway and arround town. It is well over 100.
Customer: replied 6 months ago.
Any thoughts?
Customer: replied 6 months ago.
There are no pending codes
Customer: replied 6 months ago.
Are you there?
Expert:  eautosales replied 6 months ago.
gas always has to be over 1/4 tank and the car has to be driven cold meaning don't start drive cycling after doing local errands I have had good luck with this procedure on many different models of OBD II Mercedes.I would suggest using a scan tool to clear any codes after any repairs and before performing this procedure.1- Start the car with the engine cold.2- Allow the engine to idle and reach full operating temperature (called closed loop).3 - Idle the car in gear for at least 45 seconds.4 - Accelerate to 45 MPH using no more than 1/4 throttle and maintain this speed for 10 seconds.5 - Slow to 35 – 38 MPH then maintain that speed with a steady throttle for one minute.6 - Slow to 25 MPH. operate between 25 MPH & 40 MPH for 4 minutes do not operate more than 3/4 throttle for this test segment.7 - Come to a stop and idle for at least 10 seconds.8 - Accelerate slowly to 55 MPH using no more than 1/2 throttle. Maintain 55 MPH for at least 10 seconds.9 - Continue driving between 40 & 55 MPH using a steady throttle position and maintain this for 2 minuets.I suggest you repeat this procedure at least 2 times to make sure the readiness tests are complete. If this does not work let the car cool down and add 20 minutes of hi way drivingIf you have additional questions, just let me know. Please don't forget to click accept, I am only paid after you do so.

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