Well since I replaced the Rear Lower Control Arm Bushing I have been driving the E420 more often. The Dianostic Module push button DTC code 3 was back. I would drive the car and after three ignition starts the MIL/CEL was back on again. Push the button to pull the code under the hood and then reset. The Diagnostic Module (N59) DTC Code 3 "Lambda control inoperative" continue to reappear; in addition, my air compressor clutch stop engaging. The a/c clutch would engage for a few seconds then shut off at ignition start ups.

I would scan the LH-SFI Module (N3/1) and get DTC Code 4 "Voltage at hot wire MAF sensor (B2/2) insufficient or too high, or open circuit in ground wire at hot wire MAF sensor."


Each time I drive the car these codes were sure to appear.

SOLUTION TO THIS PROBLEM:
I replaced the LH-SFI Module and no more CEL. The a/c clutch problem was solved and it also solved my so-called over heating gauge problem.

I hope this help out some of the members that is having this issue.