How to adjust Benz Engine Cooling Fan with Star Diagnosis

Decrease the Mercedes-Benz Engine Cooling Fan temperature will improve the performance of the air conditioner when idling on very hot days. This can be done via MB Star diagnosis software DAS/Xentry.

Aim:

Setting the Electric Suction Fan (Engine Cooling Fan) to operate at a temperature 10℃ below the MB OEM settings will allow the radiator fan to turn on earlier at a lower temperature to cool the engine and A/C evaporator sooner then standard.

Model tested:

Car W220 S500L 2003

Both W211 and W220 models are tested and maybe relevant to other Mercedes Benz models.

Tools needed:

MB Star diagnosis multiplexer (I am using MB Star C4)

Dell format DAS/XENTRY software HDD

Dell D630 laptop (movable HDD for any laptop with COM-port)

Instructions:

I got the SD C4 MUX with Dell 630 package, software are pre-installed. Directly open STAR XENTRY software.

In STAR Xentry go to “Control Units”

Select “Drive” control unit

Select ME-SFI 2.8-Motor electronics 2.8

Read and accept the “safety notes”

Select “Control unit adaptations”

Select “Correction programming”

Select “Electric suction fan for engine or air conditioning”

Note the existing temperature correction value

Select Button F4/F5 as required to Decrease/Increase the Temperature Correction Value

A positive temperature correction means that the suction fan is switched on sooner by the amount of the correction value.” And the button which is used in Star diagnosis Xentry is “F5: Increase temperature correction value.”

Button F4 decrease the Temperature Correction Value but will not exceed -10℃

Button F5 increase the Temperature Correction Value but will not exceed +10℃