2020 Mercedes Benz Truck ML 350 Technical Service Bulletin # LI83-30_P-0496442 Date: 120808
Air Conditioning - No Cooling Output, DTC 9006 Stored
No cooling output, fault code 9006 in air conditioning control unit
Topic number LI83.30-P-049644
Version 2
Design group 83.30 Air conditioning
Date 08-08-2012
Validity All veh. of model series 164/251
Reason for change Solution description revised
Complaint:
No cooling output, fault code (FC) 9006 stored in air conditioning (AAC) control unit.
Cause:
^ Poor system ground at ground point W29/2
^ Faulty software in AAC control unit
^ Poor ground of refrigerant compressor
Remedy:
1. Check ground point W29/2 (A-pillar, see WIS documents in attachment for details) and repair if necessary.
2020 Mercedes Benz Truck ML 350 4MATIC (164.186) V6-3.5L (272.967) Page 21
-> Optimize contact, tightening torque: 9 Nm.
2. Check crimping of ground line of AAC control unit at ground point W29/2 and repair if necessary.
In vehicles produced prior to 04/2010:
3. Flash AAC control unit with flashware (FW) 2519021300 using Star Diagnosis.
Then perform the following test on the vehicle:
4. Perform the Star Diagnosis tests stored after fault code 9006, including the test of the refrigerant compressor.
5. Check ground line between AAC control unit and ground point W29/2 for open circuit and repair if necessary.
6. Check positive line between AAC control unit and refrigerant compressor for open circuit and repair if necessary.
7. From the connection of the regulation valve on the refrigerant compressor one cable with a cable lug is bolted onto the housing of the
refrigerant compressor as a ground line; the other cable goes via the connector to the engine wiring harness.
An additional ground line with a cross section of 0.75 mm must be properly routed from the bolt-on point of the ground cable on the housing
of the refrigerant compressor to ground point W16/4 in the front right of the engine compartment below the engine hood hinge (see photos in
attachment).
Replacing the refrigerant compressor and the A/C operating unit does not remedy the problem in this case.
Attachments
Symptoms
Control unit/fault code
WIS-References
2020 Mercedes Benz Truck ML 350 4MATIC (164.186) V6-3.5L (272.967) Page 22
