Complaint
Red coolant warning in instrument cluster.
Fault codes U019F00 or U019F87 current/stored in MRG1 control unit.
Cause
Various causes
Remedy
Perform guided test for fault code U019F with XENTRY diagnosis.
Verify the following connections are clean and tight. Correct any problems and retest pump actuation:
-12V plug at M75/11
-48V plug at M75/11
-48V connector X192/4
-Connections at 48V fuse box F153/2
-Sockets 1,2, and 5 at connector 2 of MRG1 control unit
-M75/11 circuit 41 ground
If actuation and above connections are OK, but resistance between M75/11 and engine block is less than 2 ohms or
heat shield touching coolant pump, proceed with below steps.
