Vehicle position icon constantly leaves road, moves erratically, is very far from actual position

Vehicle position icon constantly leaves road, moves erratically, is very far from actual position

Diagnostic Test: Yaw Rate and Car status

NOTE:
- This is not the same condition as when driving off-road (or on a fire or logging road). This condition is caused by a loss of map matching from a bad sensor input. Check for aftermarket or other objects that can block the GPS signal. Always perform Map matching before proceeding with the troubleshooting.
- Always make sure that the correct DVD color and version are installed.
- Check on-line for service bulletins or other service information for the navigation system.

1. Check the GPS icon on the navigation picture.

Is the GPS icon white or missing?

YES - Do the troubleshooting for GPS icon is white or not shown.

NO - Go to step 2.

2. Go into the Diagnostic mode and use the "Yaw Rate" diagnostic to check the yaw rate sensor.

Is the yaw rate sensor OK?

YES - Go to step 3.

NO - Replace the navigation unit.

3. Go into the Diagnostic mode and use the "Car Status" diagnostic to check the vehicle speed pulse (VSP) and the BACK signals.

Are the vehicle speed pulse and the BACK signals OK?

YES - The problem may be a characteristic of the system. Check to see if the problem occurs in the same place in a known-good vehicle. If it does, the problem could be in the database. Go to step 4.

NO
- If the problem is the vehicle speed pulse, troubleshoot the vehicle speed signal circuit. LT BLU wire for open or short. If OK, swap a known-good ECM/PCM. If the problem or symptom goes away, replace the original ECM/PCM.
- If the BACK signal is indicated ON (I), when in any shift lever position other than reverse, troubleshoot the back-up light switch circuit or MICU(A/T models).

4. Substitute a known-good navigation unit and check to see if the problem occurs in the same place.

Does the problem occur in the same place?

YES - The problem is in the database and should be considered a characteristic of the system. Report the problem according to the Navigation System Owner's Manual under "Reporting Errors" and look for improvements in future databases.

NO - Replace the navigation unit.