Pinpoint Test C: The Compass Is Inoperative

WARNING: This page is about a different car, the 2006 Mercury Milan, 2006 Lincoln Zephyr, and 2006 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.

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

C1 CHECK CIRCUIT CBP19 (BN/WH) FOR BATTERY VOLTAGE
- Key in OFF position.
- Disconnect: Compass Module C909.
- Key in ON position.
- Measure the voltage between the compass module C909-3, circuit CBP19 (BN/WH), harness side and ground.
  
  Fig 1: Checking Circuit CBP19 (BN/WH) For Battery Voltage
- Is the voltage greater than 10 volts?
Yes : GO to C2.

No : VERIFY the SJB fuse 28 (10A) is OK. If OK, REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
C2 CHECK CIRCUIT GD139 (BK/YE) FOR AN OPEN
- Key in OFF position.
- Measure the resistance between the compass module C909-4, circuit GD139 (BK/YE), harness side and ground.
  
  Fig 2: Checking Circuit GD139 (BK/YE) For Open
- Is the resistance less than 5 ohms?
Yes : GO to C3.

No : REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
C3 CHECK CIRCUIT VMC30 (BU/GY) FOR AN OPEN AND A SHORT TO GROUND
- Disconnect: Instrument Cluster C220.
- Measure the resistance between the compass module C909-2, circuit VMC30 (BU/GY), harness side and the instrument cluster C220-17, circuit VMC30 (BU/GY), harness side; and between the compass module C909-2, circuit VMC30 (BU/GY), harness side and ground.
  
  Fig 3: Checking Circuit VMC30 (BU/GY) For Open And Short To Ground
- Is the resistance less than 5 ohms between the compass module and the instrument cluster, and greater than 10,000 ohms between the compass module and ground?
Yes : GO to C4.

No : REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
C4 CHECK CIRCUIT VMC31 (YE/GN) FOR AN OPEN AND A SHORT TO GROUND
- Disconnect: Instrument Cluster C220.
- Measure the resistance between the compass module C909-1, circuit VMC31 (YE/GN), harness side and the instrument cluster C220-16, circuit VMC31 (YE/GN), harness side; and between the compass module C909-1, circuit VMC31 (YE/GN), harness side and ground.
  
  Fig 4: Checking Circuit VMC31 (YE/GN) For Open And Short To Ground
- Is the resistance less than 5 ohms between the compass module and the instrument cluster, and greater than 10,000 ohms between the compass module and ground?
Yes : INSTALL a new compass module. SET the zone. REFER to COMPASS ZONE ADJUSTMENT in this section. CALIBRATE the compass. REFER to COMPASS CALIBRATION in this section. CLEAR the DTCs. REPEAT the self-test.

No : REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.