Hi,
Just bought a 2009 CLK550 and had a question about the error codes if I replace the interior bulbs with LEDs. Does the PCM only monitor the exterior bulbs or interior ones as well? If I replace the interior bulbs with LEDs (non resistor loaded) will the PCM throw out error messages? Thanks.

 

You will be ok. No errors

 

Thanks for your replies dynomite and guofan (PM). Do you guys know what I can use for the map light bulbs? Can I use the step light bulbs for the maps reading lights?

 

Map lights is not an easy job. Read my thread on the LEDs.