GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The circuitry is internal to the navigation module (NAV). The system does not function when the internal temperature reaches 70°C (158°F) or above. This feature prevents heat damage to internal components.

Conditions for Running the DTC

    • The navigation module (NAV) detects a power mode transition from OFF-ASLEEP to ON.
    • The NAV attempts a read from the CD or when a new CD is inserted.
    • Neither DTC B1328 nor DTC B1327 is current.

Conditions for Setting the DTC

The navigation module (NAV) is unable to read the CD because of a laser focus error, there is a table of contents error or the CD laser head temperature is above 70°C (158°F).

DTC B2464 does not set if DTC B1328 or DTC B1327 is current.

Action Taken When the DTC Sets

    • No map or blue screen appears on the display and index is not usable.
    • Navigation buttons do not function.
    • This failure has no effect outside the navigation system.

Conditions for Clearing the DTC

    • A current DTC clears when the navigation module (NAV) detects a read from a navigation CD.
    • The laser head temperature cools to less than 70°C (158°F)

Diagnostic Aids

Important: If DTC B2463 or B2465 is also set with DTC B2464, service B2463 and B2465 before DTC B2464.

Make sure the map CD is the correct one for this system.

Cycle the ignition switch even after a successful inspection with a scan tool so initialization will occur.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. Determines if the malfunction is present.

  2. Determines if the malfunction was due to no map CD in the navigation module CD player.

Step

Action

Yes

No

1

Did you perform Diagnostic System Check - Navigation System ?

Go to Step 2

Go to Diagnostic System Check - Navigation System

2

Access the internal DTCs for the navigation module (NAV).

Is the internal DTC 6 set?

Go to Step 3

Go to Step 4

3

  1. Turn OFF the ignition.
  2. Open, then close the driver door to cancel RAP.
  3. Allow the navigation module (NAV) to cool until the internal DTC 6 clears.
  4. Turn ON the ignition with the engine off.
  5. Use the scan tool in order to clear the DTC.
  6. Remove and reinsert the map CD.
  7. Use the scan tool in order to view the internal DTCs.

Does the internal DTC 6 reset?

Go to Step 5

Go to Step 7

4

  1. Turn OFF the ignition.
  2. Open, then close the driver door to cancel RAP.
  3. Wait one minute.
  4. Turn ON the ignition with the engine off.
  5. Use the scan tool in order to clear the DTC.
  6. Install a new map CD in the NAV.
  7. Perform the diagnostic system check. Refer to Diagnostic System Check - Navigation System .

Does the DTC reset?

Go to Step 5

Go to Step 7

5

  1. Turn OFF the ignition.
  2. Open, then close the driver door to cancel RAP.
  3. Allow the navigation module (NAV) to cool for one hour.
  4. Turn ON the ignition with the engine off.
  5. Use the scan tool in order to clear the DTC.
  6. Remove, then insert the map CD.
  7. Use the scan tool in order to view the internal DTCs.

Is the internal DTC 6 set?

Go to Step 6

Go to Step 7

6

Replace the navigation module (NAV). Refer to Navigation Data Processor Replacement .

Did you complete the repair?

Go to Step 7

--

7

  1. Use the scan tool in order to clear the DTC.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK