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Ask Lou P. master tech Your Own Question
Lou P. master tech
Lou P. master tech, Mercedes Technician
Category: Mercedes
Satisfied Customers: 3725
Experience:  15 years master certified 100% fix rate and have access to factory radio codes, wiring, and instructions.
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WE HAVE A 2010 GLK350 WITH CODE 0688, P0688 CLEARS AND

Customer Question

WE HAVE A 2010 GLK350 WITH CODE 0688
JA: Just to clarify, what's the exact code? And have you tried to reset it?
Customer: P0688 CLEARS AND RETURNS ON START UP
JA: Are you hoping to fix this yourself? What have you tried so far?
Customer: I NEED TO KNOW IF THERE IS A POWER RELAY FOR THE PCM OR IS ITPART OF THE ECM ITSELF THANKS
JA: Anything else you think the mechanic should know?
Customer: NO
Submitted: 3 months ago.
Category: Mercedes
Expert:  Lou P. master tech replied 3 months ago.

Hello my name is ***** ***** i will do my best to help you.I am looking over your info now and will reply back soon with some info , thanks!

Expert:  Lou P. master tech replied 3 months ago.

0688-This fault can be ignored and erased.

that is what i find for this fault code, usually it will not appear by itself, usually there is another code in conjunction.

and usually a code like this will not set off the light. what kind of scan tool are you using?

Customer: replied 3 months ago.
Snap on modis I did not see any other codes 688 code returns as soon as I restart vehicle car has no other issues showing
Expert:  Lou P. master tech replied 3 months ago.

ok , then you need a mercedes scan tool. your scanner is not picking up all the codes. you may want to run by the dealer and have then do a code scan and printout all the codes.