Pinpoint Test A: No Communication With The Front Electronic Module (Fem)

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

A1 CHECK CIRCUIT 29-DK20 (OG/GN) AND 29S-DK21 (OG/WH) FOR VOLTAGE
- Key in OFF position.
- Disconnect: FEM C201a.
- Disconnect: FEM C201c.
- Key in ON position.
- Measure the voltage between the FEM C201a-1, circuit 29S-DK22 (OG/WH), harness side and ground and between FEM C201c-6, circuit 29-DK20 (OG/GN), harness side and ground.
  
  Fig 1: Measuring Voltage Between FEM C201a-1, Circuit 29S-DK22 And Ground And Between FEM C201c-6, Circuit 29-DK20 And Ground
  Courtesy of FORD MOTOR CO.
- Are the voltages greater than 10 volts?
- Yes : GO to A2.
- No : REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.

A2 CHECK THE FEM GROUND CIRCUITS FOR AN OPEN

Key in OFF position.

Using the following table, measure the resistance between the FEM connector, harness side and ground:

Connector-Pin	Circuit
C201a-11	31-DK20A (BK/RD)
C201a-13	31-DK20B (BK/RD)
C201a-14	31-DK20C (BK/RD)
C201a-15	31-DK20D (BK/RD)
C201c-12	31-DK20 (BK/RD)

Fig 2: Measuring Resistance Between FEM Connectors And Ground

Courtesy of FORD MOTOR CO.

Are the resistances less than 5 ohms?

Yes : REFER to MODULE COMMUNICATIONS NETWORK to diagnose the communication network.
No : REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.