Pinpoint Test A: The Compass Is Inaccurate/Inoperative
Electronic Compass
Pinpoint Tests
Pinpoint Test A: The Compass Is Inaccurate/Inoperative
Refer to Wiring Diagram Set 102, Overhead Console for schematic and connector information. Diagrams By Number
Normal Operation
The compass receives battery voltage from the Smart Junction Box (SJB) fuse 43 (10A) through circuit CBP43 (GY). Ground for the compass is provided by circuit GD126 (BK/WH). The display is backlit only when the headlamp switch is in the PARK or the HEADLAMPS ON positions.
The compass and ambient air temperature display can be turned off and on by pressing the SELECT switch in the overhead console. The vehicle heading is displayed as N, NE, E, SE, S, SW, W, or NW.
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- Compass zone setting
- Compass calibration
- Compass and ambient air temperature display
- Panel illumination system concern
PINPOINT TEST A: THE COMPASS IS INACCURATE/INOPERATIVE
NOTE: After installing a new compass, always set the zone and calibrate.
NOTE: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to Battery.
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A1 CHECK THE OVERHEAD COMPASS DISPLAY
- Ignition ON.
- Check the overhead display.
- Does the overhead compass display remain on after prove out?
Yes
GO to A3.
No
GO to A2.
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A2 CHECK THE COMPASS MODE
- Press and release the SELECT switch on the overhead console.
- Does the overhead compass display turn on?
Yes
If the compass display turns on correctly, GO to A3.
If the compass display turns on, but the heading is inoperative/inaccurate or the display indicates VAR, GO to A4.
If the compass display turns on, but it does not display all directions, or indicates CAL, GO to A5.
No
GO to A7.
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A3 CHECK THE COMPASS DIMMING
- Turn the headlamp switch to the PARKING LAMPS ON position.
- Does the compass display dim?
Yes
TURN the headlamp switch to the OFF position. GO to A4.
No
TURN the headlamp switch to the OFF position. GO to A8.
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A4 CHECK THE COMPASS ZONE SETTING
- Set the compass to the correct zone for the vehicle geographical location. Refer to Compass Zone Adjustment Compass Zone Adjustment.
- Does the zone adjustment set correctly?
Yes
GO to A5.
No
INSTALL a new compass display (overhead console). REFER to Compass Display Service and Repair. TEST the system for normal operation.
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A5 CALIBRATE THE COMPASS
- Calibrate the compass. Refer to Compass Calibration Compass Calibration.
- Does the compass calibrate correctly?
Yes
GO to A6.
No
INSTALL a new compass display (overhead console). REFER to Compass Display Service and Repair. TEST the system for normal operation.
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A6 CHECK THE COMPASS ACCURACY
- Position the vehicle at each of the 8 directions (N, NE, E, SE, S, SW, W, NW) and verify that the displayed heading is accurate. The vehicle must be stationary for at least 10 seconds at each direction.
- Is the compass display accurate in each direction?
Yes
The compass is OK. REVIEW the operation of the compass with the customer.
No
INSTALL a new compass display (overhead console). REFER to Compass Display Service and Repair. TEST the system for normal operation.
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A7 CHECK THE VOLTAGE SUPPLY TO THE COMPASS DISPLAY
- Ignition OFF.
- Disconnect: Overhead Console C930.
- Ignition ON.
- Measure the voltage between the overhead console C930-1, circuit CBP43 (GY) harness side and ground.
- Is the voltage greater than 10 volts?
Yes
TURN the key to the OFF position. GO to A9.
No
VERIFY the SJB fuse 43 (10A) 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.
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A8 CHECK THE DIMMING CIRCUIT
- Ignition OFF.
- Disconnect: Overhead Console C930.
- Turn the headlamp switch to the PARKING LAMPS ON position.
- Measure the voltage between the overhead console C930-4, circuit VLN04 (VT/GY), harness side and ground and rotate the headlamp switch knob counterclockwise to the stop position.
- With the headlamp switch knob in the full stop (counterclockwise) position, is the voltage greater than 10 volts?
Yes
GO to A9.
No
REFER to Instrument Panel, Gauges and Warning Indicators to diagnose the instrument cluster and panel illumination.
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A9 CHECK CIRCUIT GD126 (BK/WH) FOR AN OPEN
- Disconnect: Negative Battery Cable.
- Measure the resistance between the overhead console C930-2, circuit GD126 (BK/WH), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
INSTALL a new compass display (overhead console). REFER to Compass Display Service and Repair. CONNECT the negative battery cable. TEST the system for normal operation.
No
REPAIR the circuit. CONNECT the negative battery cable. TEST the system for normal operation.
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