'94 C280 P0505 code help... - PeachParts Mercedes-Benz Forum

sjsfiji · #1 08-30-2006, 11:15 PM

Hi All,

I just retrieved the code (P0505) "Idle control system malfunction" and wondering where I should start... ICV maybe. Not sure if this model has one, but I'll check under the hood. The symptoms are as follows:

After starting, all instrument cluster lights go ON then OFF as normal, rev 'bout 600RPM...

When car's been running and operating temp is reached, the car seems to want to raise it's RPM while at STOP sign.

Once I get home and place the car in 'P', the RPM raises to 1200 and just stays there...

The C.E.L. came on a few days ago and all symptoms appears. I have since extinguised C.E.L. with scanner...

Please advise where I should start and what the most likely cause is...

Thanks,

mbdoc · #2 08-31-2006, 08:15 AM

ODB2 scanners can't access that problem, you need someone with a scanner that can access the ISC/CC computer.

That ISC computer is on the CAN network & controls the electronic accelerator.

sjsfiji · #3 08-31-2006, 11:23 AM

M.B.Doc,

Is there anything I can do without the use of the scanner to try and relieve the problem (i.e. normal checks for IDLE problems)? I was thinking of something mechanical that can be cleaned or something and if that does not work, proceed with using the scanner mentioned above. I ask 'cause I know no one that has that scanner. Should I buy my own scanner that does OBDII and the ISC/CC computer if one exists. If there is one, can you recommend one that does a myriad of things...

Regards,

mbdoc · #4 08-31-2006, 11:52 AM

Problem could be very simple & not $$$...w/o scan on that computer you can only guess..MB lists codes from 1-224..lots of possibilities incl brake lamp switch.

sjsfiji · #5 08-31-2006, 03:52 PM

Hi MBDoc,

What does this acronym mean? I planned to buy an OBDII scanner; however, since my friend has one should I buy the scanner for ISC/CC? I'm guessing this is useful for a lot of things I hope? Please advise...

Thanks,