Vehicle Position Wanders on the MAP
Symptom TroubleshootingVehicle position wanders on the map
NOTE:
- Always check the connectors for poor connections or loose terminals.
- Before troubleshooting, get the navigation system anti-theft codes.
- After troubleshooting, enter the navigation system anti theft codes.
Vehicle speed Pulse (VSP) Check
1. Test drive the vehicle.
Does the speedometer operate correctly?
YES - Go to step 2.
NO - Do the vehicle speed signal circuit troubleshooting.
2. Stop the vehicle with the engine running.
3. Perform the car status test in the system diagnosis test menu.
Is the VSP indicator ON when the vehicle is moving?
YES - Do the yaw rete sensor check.
NO - Go to step 4.
4. Turn the ignition switch OFF.
5. Disconnect the navigation unit connector C (8P).
6. Check for loose terminal at navigation unit connector C (8P).
7. Reconnect navigation unit connector C (8P).
8. Raise the vehicle, and make sure it is securely supported.
9. Turn the ignition switch ON (II), and shift into neutral.
10. Connect a voltmeter to body ground, and back probe navigation unit connector C (8P) terminal No. 6.
11. Slowly rotate one wheel with the other wheel blocked.
Does voltage pulse from 0 V to about 5 V or more?
YES - Replace the navigation unit.
NO - Repair open or short in the wire between the PCM and the navigation unit.
Yaw Rate Sensor Check
1. Perform the start-up procedure.
2. Press yaw rate.
3. The yaw rate offset and sensor should indicate 1.500 to 3.500 V with the vehicle stopped. If either is zero or five volts (0.00 V or 5.00 V), replace the navigation unit.
4. The yaw rate offset and sensor should within ±0.01 V of each other with the car stopped. The sensor value should change relative to offset as the car is turned while driving. If not, replace the navigation unit.
Example
Car stopped:
Normal Abnormal
Offset 2.526 V Offset 2.526 V
Sensor 2.516 - 2.536 V Sensor 2.623 V
Car turning:
Normal Abnormal
Offset 2.526 V Offset 2.526 V
Sensor 2.678 V Sensor 2.525 V
(Right Turn) 2.478 V (Left Turn) (no change on turns)
NOTE: The next check will need to be done as the car driven, you may want to save this test until last. Have a helper monitor the screen as the car is driven.
5. Press tuning.
6. Test drive the vehicle straight section of highway. While driving the car, monitor the RED ARROW SHAPED ICON on the "Tuning" screen. Just under the icon, you will see term "ANG-Disp" with an angle degree number written under it (for example: -4 °)
The icon will leave a trail of "BREAD CRUMBS" as it moves across the screen from left to right. It takes approximately 1/2 mile to cover the screen.
As you drive the car the angle degree number should be 0 ° (±3 °). If after 1/2 mile the number exceeds 0 ° (±3 °), replace the navigation unit.
NOTE: This test relies on the car being driven perfectly straight for 1/2 mile. If this is not possible, the results of this test will be false. When possible compare your results to a known good car.