Pinpoint Test B: No Communication With The Navigation System Module: Overview

Test Step 

1. B1 CHECK THE RECORDED DTCS FROM THE DRIVER DOOR MODULE 
   • Use the recorded results from the driver door module self-test.
   • Are any DTCs recorded? 

   Result / Action to Take 

   1. Yes  : If DTC 2359, refer to MODULE COMMUNICATIONS NETWORK - LS to continue diagnosis of DTC B2359.
   2. No  : GO to B2.
2. B2 CHECK CIRCUITS 30-GK8 (RD/BK) AND 10-GK8 (GY/BK) FOR VOLTAGE 
   • Key in OFF position.
   • Disconnect: Navigation System Module C4209.
   • Key in ON position.
   • Measure the voltage between the navigation system module C4209-1, circuit 30-GK8 (RD/BK), harness side and ground; and between the navigation system module C4209-2, circuit 10-GK8 (GY/BK), harness side and ground.
     Fig 1: Measuring Voltage Between Navigation System Module C4209-1 And Between Navigation System Module C4209-2 Harness Side And Ground

     Courtesy of FORD MOTOR CO.
   • Are the voltages greater than 10.5 volts? 
   1. Yes  : GO to B3.
   2. No  : REPAIR the circuit in question. TEST the system for normal operation.
3. B3 CHECK CIRCUIT 31-GK8 (BK/RD) FOR AN OPEN 
   • Key in OFF position.
   • Measure the resistance between the navigation system module C4209-13, circuit 31-GK8 (BK/RD), harness side and ground.
     Fig 2: Measuring Resistance Between Navigation System Module C4209-13 Harness Side And Ground

     Courtesy of FORD MOTOR CO.
   • Is the resistance less than 5 ohms? 
   1. Yes  : REFER to MODULE COMMUNICATIONS NETWORK - LS to continue communication diagnostics.
   2. No  : REPAIR the circuit. TEST the system for normal operation.