Set compass zone function - GF54.50-P-2014GQ

MODEL 164.1 with CODE (523) MB Audio 20 radio with CODE (245) Electronic compass as of Model Year 09/Year of Modification 08 model refinement package 

MODEL 164.1 with CODE (510) Audio 20 with CD changer with CODE (245) Electronic compass as of Model Year 09/Year of Modification 08 model refinement package 

MODEL 164.1 with CODE (525) MB Audio 50 APS radio with CODE (245) Electronic compass as of Model Year 09/Year of Modification 08 model refinement package 

MODEL 164.1 with CODE (511) Audio 50 APS with DVD changer with CODE (245) Electronic compass as of Model Year 09/Year of Modification 08 model refinement package 

MODEL 164.8 with CODE (523) MB Audio 20 radio with CODE (245) Electronic compass as of Model Year 09/Year of Modification 08 

MODEL 164.8 with CODE (510) Audio 20 with CD changer with CODE (245) Electronic compass as of Model Year 09/Year of Modification 08 

MODEL 164.8 with CODE (525) MB Audio 50 APS radio with CODE (245) Electronic compass as of Model Year 09/Year of Modification 08 

MODEL 164.8 with CODE (511) Audio 50 APS with DVD changer with CODE (245) Electronic compass as of Model Year 09/Year of Modification 08 

MODEL 251.0 with CODE (523) MB Audio 20 radio with CODE (245) Electronic compass as of Model Year 09/Year of Modification 08 

MODEL 251.0 with CODE (510) Audio 20 with CD changer with CODE (245) Electronic compass as of Model Year 09/Year of Modification 08 

MODEL 251.0 with CODE (525) MB Audio 50 APS radio with CODE (245) Electronic compass as of Model Year 09/Year of Modification 08 

MODEL 251.0 with CODE (511) Audio 50 APS with DVD changer with CODE (245) Electronic compass as of Model Year 09/Year of Modification 08 

MODEL 251.1 with CODE (523) MB Audio 20 radio with CODE (245) Electronic compass as of Model Year 09/Year of Modification 08 

MODEL 251.1 with CODE (510) Audio 20 with CD changer with CODE (245) Electronic compass as of Model Year 09/Year of Modification 08 

MODEL 251.1 with CODE (525) MB Audio 50 APS radio with CODE (245) Electronic compass as of Model Year 09/Year of Modification 08 

MODEL 251.1 with CODE (511) Audio 50 APS with DVD changer with CODE (245) Electronic compass as of Model Year 09/Year of Modification 08 

Function requirement 

• Circuit 30

General 

The electronic compass (B26) uses the earth's magnetic field to determine the cardinal points.

The earth's magnetic poles (North/South) deviate however slightly from the geographical poles. The magnetic axis of the earth is inclined by approx. 15° compared to the earth's rotation axis. If the cardinal compass points are to be determined with the aid of the earth's magnetic field, correction factors must be taken into account for various earth zones. To this end, 15 different compass zones are calculated.

At each location within a zone the deviation (declination) is approximately identical. If the correct compass zone is entered in the electronic compass, the earth's magnetic information can be corrected accordingly by the electronic compass and then the direction given relatively accurately (10°).

The 15 different compass zones are listed in the following separate service information:

• Setting compass zone, description 

Operating instruction 

The compass zones (declination) are set as follows:

• Determine appropriate compass zone (1 to 15) using zone maps (declination maps)
• Activate status "circuit 15 ON"
• Press system selection button (S110s3) repeatedly until menu "Settings" appears on multifunction display (A1p13) of instrument cluster (A1)
• Press + and - button (adjustment of specific functions and volume control (S111s1)) repeatedly until sub-menu "Vehicle" appears on multifunction display of instrument cluster
• Press scroll forward/back button (S110s1) repeatedly until message "Compass Setting zone" appears on multifunction display of instrument cluster
• Set appropriate compass zone using + and - button (adjustment of specific functions and volume control)

Examples for compass zone:

• San Francisco:
  • North America zone map gives compass zone 4
• Berlin:
  • Europe/Africa zone map gives compass zone 8
• Bonn:
  • Europe/Africa zone map gives compass zone 9

To achieve as accurate a course display as possible, it may be necessary under certain conditions to change the compass zone during a route. For example 2 compass zones are driven through on the trip from Bonn to Berlin.

Function sequence 

The status "circuit 5R ON" is placed on the interior CAN by the EIS [EZS] control unit (N73).

The control signals from the left multifunction steering wheel button group (S110) and right multifunction steering wheel button group (S111) are forwarded to the instrument cluster via the following path:

• Steering LIN
• Steering column tube module (N80)
• Engine compartment CAN

The electronic compass measures the direction of the near-earth magnetic field and sends the direction information cyclically (every t = 1 s) to the instrument cluster via the interior CAN.

	Electrical function schematic "Setting compass zone"	Model 164	PE54.50-P-2052-97MAA
		Model 251	PE54.50-P-2052-97RAA
	Instrument cluster, component description	A1	GF54.30-P-6000GM
	Electronic compass component description	B26	GF54.50-P-4102GQ
	Component description for the EZS control unit	N73	GF80.57-P-6003GM
	Component description for the steering column module control unit	N80	GF54.21-P-6051GM
	Setting compass zone, description		GF54.50-P-2014-01GQ