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

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

U1 CHECK CIRCUIT 29-DK20 (OG/GN) AND 29S-DK21 (OG/WH) FOR VOLTAGE
- Key in OFF position.
- Disconnect the FEM C201a.
- Disconnect the 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: Checking Circuit 29-DK20 (OG/GN) And 29S-DK21 (OG/WH) Voltage
  Courtesy of FORD MOTOR CO.
- Are the voltages greater than 10 volts?
Result / Action to Take
1. Yes : GO to U2.
2. No : REPAIR the circuit in question. TEST the system for normal operation.

U2 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:

FEM CONNECTOR, HARNESS SIDE AND GROUND RESISTANCE

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: Checking FEM Ground Circuits For Open

Courtesy of FORD MOTOR CO.

Are the resistances less than 5 ohms?

Yes : Go To PINPOINT TEST B: THE FRONT ELECTRONIC MODULE (FEM) DOES NOT RESPOND TO THE DIAGNOSTIC TOOL .
No : REPAIR the circuit in question. TEST the system for normal operation.