Pinpoint Test A: The Compass Is Inoperative

Electronic Compass

Pinpoint Tests

Pinpoint Test A: The Compass Is Inoperative

Refer to Wiring Diagram Set 124, Power Mirrors for schematic and connector information. Diagrams By Number

Normal Operation

The compass module (integral to the auto-dimming interior mirror) provides vehicle directional inputs to the Instrument Panel Cluster (IPC), which sends the compass information to the Front Display Interface Module (FDIM) over the Medium Speed Controller Area Network (MS-CAN). The FDIM displays the compass direction according to the information that has been provided by the compass module to the IPC.

- DTC U0161:87 (Lost Communication With Compass Module: Missing Message) - sets when the IPC does not receive any communications from the compass module.
- DTC U0161:92 (Lost Communication With Compass Module: Performance or Incorrect Operation) - sets when the IPC attempts a self-test of the compass module and its associated circuits and a failure results.

This pinpoint test is intended to diagnose the following:

- Fuse(s)
- Wiring, terminals or connectors
- Compass module (integral to the auto-dimming interior mirror)
- FDIM
- IPC

PINPOINT TEST A: 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.

NOTE: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to Battery.

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A1 CHECK THE COMPASS DISPLAY

- Ignition ON.
- Check the compass display in the lower LH corner of the FDIM.
- Does the compass display illuminate?

Yes
If the compass display illuminates with only 2 bars, GO to A2.

If the compass display turns on, but it does not display all directions, or indicates CAL, GO to Pinpoint Test B. Pinpoint Test B: The Compass Is Inaccurate

No
REFER to Accessories and Optional Equipment.

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A2 CHECK THE COMPASS MODULE VOLTAGE SUPPLY

- Ignition OFF.
- Disconnect: Auto-Dimming Interior Mirror C911 (Without Camera Mirror, Without SYNC).
- Disconnect: Auto-Dimming Interior Mirror C9012 (Without Camera Mirror, With SYNC).
- Disconnect: Auto-Dimming Interior Mirror C9039 (With Camera Mirror).
- Ignition ON.
- Measure the voltage between the auto-dimming interior mirror, harness side and ground as follows:

- Is the voltage greater than 10 volts?

Yes
GO to A3.

No
VERIFY the Smart Junction Box (SJB) fuse 41 (15A) is OK. If OK, REPAIR the circuit. TEST the system for normal operation. If not OK, Refer to the Wiring Diagrams to identify the possible causes of the circuit short Diagrams By Number.

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A3 CHECK THE COMPASS MODULE GROUND FOR CONTINUITY

- Ignition OFF.
- Disconnect: Negative Battery Cable.
- Measure the resistance between the auto-dimming interior mirror, harness side and ground as follows:

- Is the resistance less than 5 ohms?

Yes
GO to A4.

No
REPAIR the circuit. TEST the system for normal operation.

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A4 CHECK THE DTCs

- Connect: Negative Battery Cable.
- Connect: Auto-Dimming Interior Mirror C911, C9012 or C9039.
- Ignition ON.
- Clear the FDIM DTCs.
- Ignition OFF.
- Ignition ON.
- Wait 10 seconds.
- Retrieve the FDIM DTCs.
- Is DTC U0155:00 present?

Yes
REFER to Accessories and Optional Equipment.

No
GO to A5.

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A5 CHECK THE COMPASS SIGNAL CIRCUITS FOR A SHORT TO VOLTAGE

- Ignition OFF.
- Disconnect: Auto-Dimming Interior Mirror C911, C9012 or C9039.
- Disconnect: IPC C220.
- Measure the voltage between the auto-dimming interior mirror, harness side and ground as follows:

- Is any voltage present?

Yes
REPAIR the circuit in question. TEST the system for normal operation.

No
GO to A6.

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A6 CHECK THE COMPASS SIGNAL CIRCUIT FOR AN OPEN OR SHORT TO GROUND

- Ignition OFF.
- Measure the resistance between the auto-dimming interior mirror, harness side and the IPC, harness side; and between the auto-dimming interior mirror, harness side and ground as follows:

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

Yes
GO to A8.

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

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A8 CHECK FOR DTC U0161:87 OR DTC U0161:92

- Connect: IPC C220.
- Connect: Auto-Dimming Interior Mirror C911, C9012 or C9039.
- Ignition ON.
- Clear the IPC DTCs.
- Ignition OFF.
- Ignition ON.
- Wait 10 seconds.
- Retrieve the IPC DTCs.
- Is DTC U0161:87 or DTC U0161:92 present?

Yes
INSTALL a new auto-dimming interior mirror. REFER to Mirrors. ADJUST the zone setting. REFER to Compass Zone Adjustment Compass Zone Adjustment. CALIBRATE the compass. REFER to Compass Calibration Compass Calibration. TEST the system for normal operation.

No
GO to A9.

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A9 CHECK FOR CORRECT IPC OPERATION

- Disconnect the IPC connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the IPC connector and make sure it seats correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?

Yes
INSTALL a new IPC. REFER to Instrument Panel, Gauges and Warning Indicators. CLEAR the DTCs. REPEAT the self-test. 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. CLEAR the DTCs. REPEAT the self-test.

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