Pinpoint Test AM: The Compass Is Inoperative

Instrumentation, Message Center and Warning Chimes

Pinpoint Test AM: The Compass Is Inoperative


Normal Operation

The auto-dimming interior mirror receives voltage from the Smart Junction Box (SJB). The auto-dimming interior mirror communicates the vehicle direction to the Instrument Panel Cluster (IPC) through the compass communication data plus circuit and compass communication data minus circuit from the compass module (integrated into the auto-dimming interior mirror).

- DTC U0161:00 (Lost Communication With Compass Module)- sets in continuous memory in the IPC (Instrument Panel Cluster) if the IPC (Instrument Panel Cluster) fails to receive the compass data from the compass module (located in auto-dimming interior mirror). If the IPC (Instrument Panel Cluster) fails to receive the compass data, the IPC (Instrument Panel Cluster) sets DTC U0161:00 and defaults the compass display to (--).

This pinpoint test is intended to diagnose the following:

- Fuse

- Wiring, terminals or connectors

- Auto-dimming interior mirror

PINPOINT TEST AM : THE COMPASS IS INOPERATIVE

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

AM1 CHECK THE AUTO-DIMMING INTERIOR MIRROR VOLTAGE SUPPLY

- Ignition OFF.

- Disconnect: Auto-Dimming Interior Mirror C9012 (With Microphone) or C9039 (With Rear Video Camera).

- Ignition ON.

- On mirrors with a microphone, measure the voltage between the auto-dimming interior mirror C9012-1, circuit CBP41 (BU), harness side and ground.





- On mirrors with a rear video camera display, measure the voltage between the auto-dimming interior mirror C9039-1, circuit CBP41 (BU), harness side and ground.





Is the voltage greater than 10 volts?

Yes
GO to AM2.

No
VERIFY the SJB (Smart Junction Box) fuse 41 (15A). If OK, REPAIR circuit CBP41 (BU) for an open. CLEAR the DTCs. REPEAT the self-test. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short Electrical Diagrams.

AM2 CHECK THE COMPASS MODULE GROUND CIRCUIT FOR AN OPEN

- Ignition OFF.

- Disconnect: Negative Battery Cable.

- On mirrors with a microphone, measure the resistance between the auto-dimming interior mirror C9012-10, circuit GD133 (BK), harness side and ground.





- On mirrors with a rear video camera display, measure the resistance between the auto-dimming interior mirror C9039-3, circuit GD133 (BK), harness side and ground.





Is the resistance less than 5 ohms?

Yes
GO to AM3.

No
REPAIR circuit GD133 (BK) for an open. CLEAR the DTCs. REPEAT the self-test.

AM3 CHECK THE COMPASS COMMUNICATION DATA PLUS CIRCUIT FOR AN OPEN AND SHORT TO GROUND

- Disconnect: IPC (Instrument Panel Cluster) C220.

- On mirrors with a microphone, measure the resistance between the IPC (Instrument Panel Cluster) C220-4, circuit VMC31 (GY/BU), harness side and the auto-dimming interior mirror C9012-6, circuit VMC31 (GY/BU), harness side; and between the IPC (Instrument Panel Cluster) C220-4, circuit VMC31 (GY/BU), harness side and ground.





- On mirrors with a rear video camera display, measure the resistance between the IPC (Instrument Panel Cluster) C220-4, circuit VMC31 (GY/BU), harness side and the rear video camera display mirror C9039-9, circuit VMC31 (GY/BU), harness side; and between the IPC (Instrument Panel Cluster) C220-4, circuit VMC31 (GY/BU), harness side and ground.





Is the resistance less than 5 ohms between the IPC (Instrument Panel Cluster) and the auto-dimming interior mirror, and greater than 10,000 ohms between the IPC (Instrument Panel Cluster) and ground?

Yes
GO to AM4.

No
REPAIR circuit VMC31 (GY/BU) for an open or short to ground. CLEAR the DTCs. REPEAT the self-test.

AM4 CHECK THE COMPASS COMMUNICATION DATA MINUS CIRCUIT FOR AN OPEN AND SHORT TO GROUND

- On mirrors with a microphone, measure the resistance between the IPC (Instrument Panel Cluster) C220-3, circuit VMC30 (BU/GY), harness side and the auto-dimming interior mirror C9012-2, circuit VMC30 (BU/GY), harness side; and between the IPC (Instrument Panel Cluster) C220-3, circuit VMC30 (BU/GY), harness side and ground.





- On mirrors with a rear video camera display, measure the resistance between the IPC (Instrument Panel Cluster) C220-3, circuit VMC30 (BU/GY), harness side and the rear video camera display mirror C9039-10, circuit VMC30 (BU/GY), harness side; and between the IPC (Instrument Panel Cluster) C220-3, circuit VMC30 (BU/GY), harness side and ground.





Is the resistance less than 5 ohms between the IPC (Instrument Panel Cluster) and the auto-dimming interior mirror, and greater than 10,000 ohms between the IPC (Instrument Panel Cluster) and ground?

Yes
INSTALL a new auto-dimming interior mirror. SET the zone. REFER to Compass Zone Adjustment Compass Zone Adjustment. CALIBRATE the compass. REFER to Compass Calibration Compass Calibration. CLEAR the DTCs. REPEAT the self-test.

No
REPAIR circuit VMC30 (BU/GY) for an open or short to ground. CLEAR the DTCs. REPEAT the self-test.