Hello,
I just bought my first MB a few days ago. It is a 1995 E320 with 155k miles. She is in great shape and runs well. The idle is a little rough (around 600 rpms) and the CE light stays on and I got fault codes 4, 6 and 18 from the LED diagnostics. I found some trash on the intake side of the air filter. I removed and cleaned the box and blew out the filter. I also ordered a new filter that will arrive tomorrow. I will clean the Mas Air Flow Sensor tomorrow. If that does not clear code 4, I will replace the sensor. I have now idea where to start with the other two faults, 6 (Idle speed control faulty) and 18 (Adjustable camshaft timing solenoid circuit open or circuit short). Is there some troubleshooting I can do before replacing and parts. Where are these parts and how do I access them. I am a very capable DIYer or else I would not have purchased this car. There isn't much help in the owner's manual and thanks to this forum I was able to find the oil filter. I do not know if the wiring harness has been replaced. I will inspect for cracks and and other signs of deterioration. This weekend. Any help will be I can get on these fault codes will be appreciated.

Thanks in advance

Shawn H
King George, VA

You are on the right track.

Start by erasing ALL of those codes, then drive until check engine comes back on.

Code 6 suggests an issue with the electronic accelerator system.
TO diagnosis correctly, you need a scanner to read codes from that computer.

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Thanks, I'll do that and see what happens. I have read there are plans out here some place for building a homemade scanner but cannot find a working link.