susainav

Hi!
My check engine light came on recently, but the care drives fine. My concern is that when I got my Service B done at a good european car shop, he did not not reset the FSS and I just ignored. Of course, the service exceed message kept coming and I ignored it and was wondering if that may have tripped the CEL light.

I tried to reset the FSS indicator and it won't let me do it anymore. Anyone know what can be done.

Thanks

2004 C230K sedan

tbenz

the fss has nothing to do with the ck eng light, the ck eng light comes on do to emission related faults, you could have a bad gas cap or loose, you can bring the car back to the place that did your serv and have them reset your fss

susainav

Thanks TBenz,

Hopefully this does not set me back too much. I have a feeling it might be a bad gas cap, but who knows. We filled up gas and I my wife did not close it right, but atleast told me about it at the gas station itself. I would say the tank was not closed properly for about 5 mins and within 10 mins of leaving the station, the light came on.

tbenz

if you corrected the gas cap the light will go out on its own after a couple of days

electromethod

hopefully it's not the "oil in the wiring harness" issue. I had the same happen couple of months ago. When I pulled the code, mine only said the 2nd o2 sensor was bad.... then found out the wiring harness had oil in it. Ugh..... there went 4 years of reliability out the window! Pull the codes and post them up so people can help you diagnose it. Good luck!

susainav

Thanks to electromethod and his NOOB tutorial.

Just got it checked out and P0128 is the Code. Checked the coolant level and it looks right. Any thoughts please?

electromethod

P0128 Coolant Thermostat (Coolant Temp Below Thermostat Regulating Temperature)

You checked the coolant level correctly? The only reason I ask is that a lot of us are sweating the valeo radiators that leak coolant into transmission. Otherwise, hope it's just a thermostat....... knock on wood.

susainav

Will double check the coolant level as you suggest. Any idea on how much replacing a defective thermostat or an ECT sensor would cost?

Buellwinkle

Shouldn't take much time to change either, figure a dealer is going to charge a minimum of 1 hour labor. What happened on my old 2002 C230 is the car would not warm up in a pre-allotted time in the winter months (it gets really cold here, 15C today, arghh) and then trip the CEL with that code. This means the thermostat is probably stuck open. Just plug in your OBD2 scanner and monitor coolant temp, or if you are scanner challenged, use the coolant temp reading on your dash and see if it takes too long for it to fully warm up, if I remember, it should reach about 80C for normal operating temp.

susainav

Thanks Buellwinkle. My temp readout in the car gets upto 80, ut it takes some time. I keep chacking it just in case of a overheat and it never gets uppast 80-81. So I was not too worried about it, nevertheless, I want to get this fixed just in case worse problems arise from this.

ayilar

Had this happen to me a month ago on my 2005 C230k -- CEL on, closing the gas tank lid without effect, engine seemingly running fine.

Turned out to be a bad thermostat. Replaced under warranty (part had to be ordered from Germany, arrived a week later; dealer told me to keep driving the car in the menatime).

Good luck!

BabyBenz6spd

I got my "check engine" light on last night and went to the local Advanced Auto Part store to get the code pulled. Turns out to be "coolant below regulating temperature", I guess I'm in the same boat as you.......have my appointment set with the dealer tomorrow, I'm out of warranty already......I hope the thermostat is not gonna cost me arm and a leg!

BabyBenz6spd

After coming back from the dealer this afternoon, it turns out the thermostat needs to be replaced for $400! dang!!

cbwdevil

Really? That much? Thermostat is only $30 plus the 1.5 hours to change it ($148.50). Total cost of job shouldn't be more than $200.00. Man they are ROBBERS!!!! GL!!!

Buellwinkle

Haha, could have done it yourself and saved $380 or taken it to Pep Boys and have them do it for $100 or less. At least in my neck of the woods, the Pep Boys mechanics are far superior and much less likely to rip you off than the incompetent mechanics at MB of Laguna Niguel. Heck, they mess up my last oil change (that's the 3rd time they messed up an oil change but it's free, part of my 4 yrs free maintenance).

jaird23

I just got my thermostat done 2day and I paid $183.00!