TSB L101.30-P-051567 PDF

A service bulletin addressing issues with the check engine light and low coolant indicator for Mercedes-Benz vehicles equipped with the M156 engine. It outlines a complaint about CEL illumination and engine misfiring due to coolant entering the engine oil, possibly because of a broken cylinder head bolt. The recommended remedy involves removing cylinder heads, measuring piston deck height, replacing necessary parts, and changing engine oil and filter. Symptoms include various cooling system indicator alerts. Relevant parts and work units are listed, with references for additional guidance.