Part 4

Navigation System Diagnostic Mode (Continued)

GPS Information

This screen shows the current status of GPS reception. The circular diagram shows the current location of the GPS satellites (yellow numbers) as they would appear in the sky. The outer circle represents the horizon (0 degrees elevation). The middle and inner circles represents 30 and 60 degrees respectively. The very center of the diagram (90 degrees elevation) is directly overhead. Nearby obstructions, like tall buildings will block satellites in that direction. That is why it is necessary to be in an open area to effectively troubleshoot GPS reception issues. The satellite numbers shown on the diagram correspond to the PRN number in the GPS Details screen. There are always at least 24 active GPS satellites in orbit. Because satellites fail, and have to be removed from service, spares are always parked in orbit, ready to be activated. This is why the PRN (satellite ID number) can be greater than 24.

NOTE: When you use this screen for troubleshooting, park the vehicle outside, away from buildings, tall trees, and high-tension wires for at least 10 minutes with the engine running.

- The Number of Satellites box shows the number of acquired satellites (maximum of 12). It should contain four or more icons. If not, go to GPS icon is white or not shown troubleshooting Symptom Troubleshooting.
- The Current Position shows latitude, longitude, and elevation (in feet). If there are less than four satellites, the elevation can be grossly inaccurate.
- The Date/Time field shows the current date, and also GMI time.





NOTE: Pressing the MAP/GUIDE button displays the satellite number on each circle.

GPS Detail

By pressing and holding the MENU button for 2 seconds, a GPS Detail screen appears. This screen displays real time incoming satellite positional data when the vehicle is outside in the open. The information shown on this screen is for factory use.

NOTE: The data shown is an example only.





- The box TS/AS and H DOP (horizontal dilution of precision)/V DOP (vertical dilution of precision) is for factory use.
- The Speed and Direction information is updated in real time when driving.
- The Date/Time Information is the same as in Setup screen 2 Adjust Time Zone/Clock.
- If the 3D icon is shown above the yellow dots, this implies that at least four satellites are available for map positioning, and the GPS indicator on the map screen will be green. See the Global Positioning System detailed explanation in the System Description.
- If the row of data in the table below begins with a yellow dot, the AZI and EL fields can be used to locate each satellite on the circular GPS diagram (see prior screen).

The table of values shown below define the terms at the top of the columns in the GPS detail screen.






Yaw Rate

This diagnosis checks the yaw rate sensor in the audio-navigation unit. This device detects when the vehicle turns, and repositions the vehicle position icon on the map screen. For more detailed information, see the yaw rate sensor theory of operation under System Description.

- Sensor indicates the voltage output from the yaw rate sensor. It should indicate about 2.300 V-2.700 V when the vehicle is stopped.
- Offset is the reference voltage or standard within the yaw rate sensor. It also should indicate about 2.300 V-2.700 V when the vehicle is stopped.
- A sensor output voltage HIGHER than the Offset voltage indicates that the vehicle is turning to the right.
- A sensor output voltage LOWER than the Offset voltage indicates that the vehicle is turning to the left.
- The yaw rate offset, and sensor should both indicate about 2.300 V-2.700 V when the vehicle is stopped. If either reads below 2.300 V, or above 2.700 V, replace the audio-navigation unit Audio-Navigation Unit Removal/Installation.
- The yaw rate offset and sensor should be within +/-0.01 V of each other when the vehicle is stopped. The sensor value should change relative to the offset as the vehicle turns while driving. If not, replace the audio-navigation unit Audio-Navigation Unit Removal/Installation.

Example: Car stopped





Example: Car turning





- The settings CCW Cal Factor, CW Cal Factor, and Set are for factory use only. THIS SHOULD NEVER BE ADJUSTED.
- For detailed analysis of the yaw rate select tuning.





Yaw Rate Tuning

This diagnosis allows you to graphically display problems with the yaw rate sensor.

- The ANG-Disp value accumulates any differences between the offset, and sensor voltages (see Yaw Rate diagnostic). When the sensor functions normally, the random changes in these two voltages generally cancels out, so the value is 0. However if one voltage is consistently higher than the other, then the ANG-Disp value accumulates the constant change.
- The Reset button temporarily clears the angular accumulation (ANG-Disp), and clears the display dots.
- Do not touch CCW, CW, or Set buttons. These are used for factory setup only.

Two tests are explained below. For gross problems with the sensor, the stationary test usually confirms whether the sensor is defective. For yaw rate issues related to driving, do the road test described below.

1. Stationary test: If the VP icon spins with the vehicle parked and the engine running and the ANG-Disp value slowly increases or decreases, the yaw rate sensor is defective. Replace the audio-navigation unit Audio-Navigation Unit Removal/Installation.

2. Road test: Drive the vehicle on a very straight, smooth road. Enter the diagnostic mode, select Yaw rate, and touch the Tuning button. While driving down a straight road, the white dots should trace a straight line across the screen. However, if you are driving on a straight road, and you notice the dots constantly dropping down or heading up as you drive, the audio-navigation unit's yaw sensor is defective. To run the test again, touch Reset to clear ANG-Disp, and the dotted lines.

If either test above fails, please enter Yaw rate sensor defective for the problem description, on the audio-navigation unit return form.

NOTE: CCW, CW and Set buttons are disabled and cannot be activated.






Car Status

Use this screen to confirm that the audio-navigation unit is properly receiving input signals. Signals equal to (0) are OFF, and signals equal to (1) are ON. If the value on the display does not match the actual vehicle status, then check the wire carrying the signal.

- VSP-Vehicle Speed Pulse from ECM/PCM (audio-navigation unit connector A (24P) terminal No. 15)
a) OFF (0) when vehicle is not moving
b) ON (1) when vehicle is moving

The VSP comes from the ECM/PCM as a dedicated signal. Internally, the audio-navigation unit compares the actual VP on the map against street data to adjust the pulse to speed scaling factor. As this scaling factor becomes more accurate, the Level gradually increases from 0 to 10.

- BACK-Reverse indication from taillight relay (audio-navigation unit connector H (28P) terminal No. 20)
a) OFF (0) when the shift lever is in any position other than reverse
b) ON (1) when the shift lever is in R position

The Back signal is used by the audio-navigation unit to allow the map screen to show the VP moving backwards when the vehicle is in R position. This signal is needed because the Speed Pulse has no direction indication.





- ILL-Illumination Indication(audio-navigation unit connector H (28P) terminal No. 4)
a) OFF (0) when parking lights, or headlights are off
b) ON (1) when parking lights, or headlights are on

The navigation uses the signal to determine whether to put the navigation screen into the Day or Night brightness mode. (Setup screen 1)

NOTE:

- The PARK on this diagnostic screen in this models always shows [-].
- You will not see this display when you shift into R because the screen displays the rearview camera image.

Error History

Refer to How to Check for Error History to use this diagnosis.






Guideline Setup

This screen adjusts the guide line of the rearview camera image. This is for factory use only.

NOTE: Do not change the shift lever to R while this diagnosis runs.

Select Normal View mode in the Guideline Setup menu.





- If the ALL Points is selected, all guide lines can be adjusted at the same time.
- If the Default is selected, all guide lines can be reset for the factory settings.
- For returns to the previous screen, select the CANCEL or push the CANCEL button.





Using the interface dial to adjust the point(s).






If you want to keep the setting, select Save. Each coordinates of the guide line is displayed.





Select the Exit and the guide line adjust ends (returns to the Guideline Setup menu screen).

Error Message Table