Pinpoint Test H: The Audio/Audio Navigation Unit Does Not Respond To The Diagnostic Tool

WARNING: This page is about a different car, the 2006 Mercury Montego, 2006 Ford Freestyle, and 2006 Ford Five Hundred. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION: Use the correct probe adaptor(s) when making measurements. Failure to use the correct probe adaptor(s) may damage the connector.

H1 CHECK THE AUDIO/AUDIO NAVIGATION UNIT C240C FOR DAMAGE
- Key in OFF position.
- Disconnect: Audio/Audio Navigation Unit C240c.
- Inspect the audio/audio navigation unit C240c for damage.
- Is the audio unit C240c OK?
Yes: GO to H2.

No: REPAIR the audio/audio navigation unit C240c as necessary. CARRY OUT the data link diagnostics test.
H2 CHECK THE MEDIUM SPEED CAN CIRCUITS BETWEEN THE DLC AND THE AUDIO/AUDIO NAVIGATION UNIT FOR AN OPEN
- Key in OFF position.
- Measure the resistance between the audio/audio navigation unit C240C-15, circuit 2180 (WH/BK), harness side and the DLC C251-3, circuit 2180 (WH/BK), harness side; and between the audio/audio navigation unit C240c-16, circuit 2181 (BK/YE), harness side and the DLC C251-11, circuit 2181 (BK/YE), harness side.
  
  Fig 1: Checking Medium Speed CAN Circuits Between DLC & Audio/Audio Navigation Unit
  Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?
Yes: GO to H3.

No: REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test. CARRY OUT the data link diagnostics test.
H3 CHECK FOR CORRECT AUDIO/AUDIO NAVIGATION UNIT OPERATION
- Disconnect all the audio/audio navigation unit connectors.
- Check for:
  - corrosion
  - pushed-out pins
- Connect all the audio/audio navigation unit connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes: INSTALL a new audio/audio navigation unit. REFER to REMOVAL AND INSTALLATION . CLEAR the DTCs. REPEAT the self-test. CARRY OUT the data link diagnostics test.

No: The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test. CARRY OUT the data link diagnostics test.