Navigation System Symptom Troubleshooting - Vehicle position icon constantly leaves road or is very far from actual position

Vehicle position icon constantly leaves road or is very far from actual position
  1. Check the GPS icon on the navigation picture.
Is No GPS icon shown?
YES -
NO -
Go to Step 2 .
Are the yaw rate sensor and vehicle speed pulse OK?
YES -
The problem may be normal. Check to see if the problem occurs in the same place. If it does, the problem could be in the database. Go to Step 4 .
NO -
If the problem is the yaw rate sensor, replace the navigation unit. If the problem is the vehicle speed pulse, troubleshoot the vehicle speed signal circuit.■
  1. 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. Report the problem according to the Navigation System Manual under ‘‘Reporting Errors''.■
NO -