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

WARNING: This page is about a different car, the 2004 Lincoln LS. However, it is still accessible from the selected car via links, so may be relevant.

Test Step

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.
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.
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.