2020 Mercedes Benz Truck ML 63 AMG Technical Service Bulletin # LI01-30_P-051567 Date: 110414

Page 48 Engine - MIL ON And Low Coolant Lamp ON Check engine light (CEL) on and low coolant indicator lamp lights up Topic number LI01.30-P-051567 Version 1 Design group 01.30 Cylinder head Date 04-14-2011 Validity M156 up to engine # 569xx 60 060658 Reason for change Complaint: CEL illumination, engine misfire, stalling, rough running low coolant indicator lights up. No external coolant loss detectable. Coolant in the engine oil and/or in the combustion chamber Cause: Cylinder head bolt broken. Engine coolant enters into engine oil. Coolant might be present in the combustion chamber. Affected engine number up to 1569xx 60 060658 Remedy:

1. Remove cylinder heads.
2. Measure piston deck height (specified value: 0.18 mm +/- 0.05 mm). If the measurement from the top surface of the cylinder crankcase to the

top surface of the piston is outside of the specification (the maximum deck height is 0.23 mm), the affected connecting rod with piston and bearings must be replaced.

1. Replace all cylinder head bolts.
2. Replace all hydraulic tappets.
3. Change engine oil and filter and replenish engine coolant.
4. Another oil change must be performed after about 15 mile test drive (engine must run at operating temperature).

Symptoms Parts Page 49 Work units WIS-References