Pinpoint Test M: The Navigation System Module Does Not Respond To The Diagnostic Tool

WARNING: This page is about a different car, the 2005 Lincoln Navigator and 2005 Ford Expedition. However, it is still accessible from the selected car via links, so may be relevant.

M1 CHECK THE DATA LINK CONNECTOR (DLC) C251 FOR DAMAGE
- Key in OFF position.
- Inspect the DLC C251.
- Is the DLC C251 OK?
- Yes : GO to M2.
- No : REPAIR the DLC C251. CARRY OUT the data link diagnostics test.
M2 CHECK THE NAVIGATION SYSTEM MODULE C2279A FOR DAMAGE
- Key in OFF position.
- Disconnect: Navigation System Module C2279a.
- Inspect the navigation system module C2279a for damage.
- Is the navigation system module C2279a OK?
- Yes : GO to M3.
- No : REPAIR the navigation system module C2279a. CARRY OUT the data link diagnostics test.
M3 CHECK CIRCUITS 914 (TN/OG) AND 915 (PK/LB) BETWEEN THE NAVIGATION SYSTEM MODULE C2279A AND THE DLC C251 FOR AN OPEN
Measure the resistance between the navigation system module C2279a pin 4, circuit 914 (TN/OG), harness side and the DLC C251 pin 2, circuit 914 (TN/OG), harness side.

Fig 1: Measuring Resistance Between Navigation System Module C2279A Pin 4, Circuit 914 (TN/OG) And DLC C251 Pin 2, Circuit 914 (TN/OG)
Courtesy of FORD MOTOR CO.
Measure the resistance between the navigation system module C2279a pin 16, circuit 915 (PK/LB), harness side and the DLC C251 pin 10, circuit 915 (PK/LB), harness side.

Fig 2: Measuring Resistance Between Navigation System Module C2279A Pin 16, Circuit 915 (PK/LB), Harness Side And DLC C251 Pin 10, Circuit 915 (PK/LB)
Courtesy of FORD MOTOR CO.
Are the resistances less than 5 ohms?

Yes : GO to M4.
No : REPAIR the circuit in question. CARRY OUT the data link diagnostics test.

M4 CHECK CIRCUITS 914 (TN/OG) AND 915 (PK/LB) FOR A SHORT TO GROUND
- Measure the resistance between the navigation system module C2279a pin 4, circuit 914 (TN/OG), harness side and ground.
  
  Fig 3: Measuring Resistance Between Navigation System Module C2279A Pin 4, Circuit 914 (TN/OG) And Ground
  Courtesy of FORD MOTOR CO.
- Measure the resistance between the navigation system module C2279a pin 16, circuit 915 (PK/LB), harness side and ground.
  
  Fig 4: Measuring Resistance Between Navigation System Module C2279A Pin 16, Circuit 915 (PK/LB) And Ground
  Courtesy of FORD MOTOR CO.
- Are the resistances greater than 10,000 ohms?
- Yes : GO to M5.
- No : REPAIR the circuit in question. CARRY OUT the data link diagnostics test.
M5 CHECK CIRCUITS 914 (TN/OG) AND 915 (PK/LB) FOR A SHORT TO VOLTAGE
- Key in ON position.
- Measure the voltage between the navigation system module C2279a pin 4, circuit 914 (TN/OG), harness side and ground.
  
  Fig 5: Measuring Voltage Between Navigation System Module C2279A Pin 4, Circuit 914 (TN/OG) And Ground
  Courtesy of FORD MOTOR CO.
- Measure the voltage between the navigation system module C2279a pin 16, circuit 915 (PK/LB), harness side and ground.
  
  Fig 6: Measuring Voltage Between Navigation System Module C2279A Pin 16, Circuit 915 (PK/LB) And Ground
  Courtesy of FORD MOTOR CO.
- Is any voltage present?
- Yes : GO to M6.
- No : REPAIR the circuit in question. CARRY OUT the data link diagnostics test.
M6 CHECK FOR CORRECT NAVIGATION SYSTEM MODULE OPERATION
- Disconnect all the navigation system module connectors.
- Check for:
  - corrosion
  - pushed-out pins
- Connect all the navigation system module 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 navigation system module. REFER to NAVIGATION SYSTEM . CLEAR the diagnostic trouble codes (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.