Pinpoint Test AF: The Compass Is Inoperative (Without Sync®)

NOTE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

AF1 CHECK THE AUTO-DIMMING INTERIOR MIRROR VOLTAGE SUPPLY
- Ignition OFF.
- Disconnect: Auto-Dimming Interior Mirror C911.
- Ignition ON.
- Measure the voltage between the auto-dimming interior mirror C911-1, circuit CBP32 (GN/VT), harness side and ground.
  
  Fig 1: Checking Auto-Dimming Interior Mirror Voltage Supply
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
  - Yes : GO to AF2.
  - No : VERIFY the BCM fuse 32 (15A). If OK, REPAIR circuit CBP32 (GN/VT) for an open. TEST the system for normal operation. If not OK, REFER to the appropriate SYSTEMS WIRING DIAGRAMS article to identify the possible causes of the circuit short.
AF2 CHECK THE COMPASS MODULE GROUND CIRCUIT FOR AN OPEN
- Measure the voltage between the auto-dimming interior mirror C911-1, circuit CBP32 (GN/VT), harness side and auto-dimming interior mirror C911-4, circuit GD133 (BK), harness side and ground.
  
  Fig 2: Checking Compass Module Ground Circuit For An Open
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
  - Yes : GO to AF3.
  - No : REPAIR circuit GD133 (BK) for an open. CLEAR the DTCs. REPEAT the self-test.
AF3 CHECK THE COMPASS COMMUNICATION BUS FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: BCM C2280B.
- Ignition ON.
- Measure the voltage between the auto-dimming interior mirror C911-2, circuit VDN01 (BU/WH), harness side and ground.
  
  Fig 3: Checking Compass Communication Bus For Short To Voltage
  Courtesy of FORD MOTOR CO.
- Is any voltage present?
  - Yes : REPAIR circuit VDN01 (BU/WH) for a short to voltage. CLEAR the DTCs. REPEAT the self-test.
  - No : GO to AF4.
AF4 CHECK THE COMPASS COMMUNICATION BUS FOR AN OPEN AND SHORT TO GROUND
- Disconnect: BCM C2280B.
- Measure the resistance between the BCM C2280B-52, circuit VDN01 (BU/WH), harness side and the auto-dimming interior mirror C911-2, circuit VDN01 (BU/WH), harness side; and between the BCM C2280B-52, circuit VDN01 (BU/WH), and ground.
  
  Fig 4: Measuring Resistance Between BCM C2280B-52, Circuit VDN01 (BU/WH) And Auto-Dimming Interior Mirror C911-2, Circuit VDN01 (BU/WH)
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms between the BCM and the auto-dimming interior mirror, and greater than 10, 000 ohms between the BCM and ground?
  - Yes : INSTALL a new auto-dimming interior mirror. REFER to REAR VIEW MIRRORS . SET the zone. REFER to Compass Zone Adjustment . CALIBRATE the compass. REFER to Compass Calibration . CLEAR the DTCs. REPEAT the self-test. If the compass is still inoperative, GO to AF5.
  - No : REPAIR circuit VDN01 (BU/WH) for an open or short to ground. CLEAR the DTCs. REPEAT the self-test.
AF5 CHECK FOR CORRECT BCM OPERATION
- Disconnect all the BCM connectors.
- Check for:
  - corrosion
  - damaged pins
  - pushed-out pins
- Connect all the BCM connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
  - Yes : INSTALL a new BCM. REFER to MULTIFUNCTION ELECTRONIC MODULES . TEST the system for normal operation.
  - No : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.