Pinpoint Test D: One High Beam Headlamp Is Inoperative

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.

D1 RETRIEVE THE FEM DIAGNOSTIC TROUBLE CODES (DTCs)
NOTE: Make sure the headlamp switch is in the OFF position.
- Key in OFF position.
- Connect the diagnostic tool.
- Key in ON position.
- Carry out the FEM on-demand self-test.
- Are any DTCs present?
- Yes : If DTC B1567, GO to D3.
  All others, REFER to the FEM DIAGNOSTIC TROUBLE CODE (DTC) INDEX for correct diagnostics.
- No : GO to D2.
D2 CHECK CIRCUIT 31S-LE15 (BK/GN) OR CIRCUIT 31S-LE22 (BK/GN) FOR A SHORT TO POWER
- Key in OFF position.
- Disconnect: FEM C201a.
- Disconnect: LH Headlamp C1021 or RH Headlamp C1041.
- Key in ON position.
- Measure the voltage between FEM C201a-17, circuit 31S-LE15 (BK/GN) (LH headlamp), harness side and ground; or between FEM C201a-10, circuit 31S-LE22 (BK/RD) (RH headlamp), harness side and ground.
  
  Fig 1: Measuring Voltage Between FEM C201A-17, Circuit 31S-LE15 And Ground; Or Between FEM C201a-10, Circuit 31S-LE22 And Ground
  Courtesy of FORD MOTOR CO.
- Is any voltage present?
- Yes : REPAIR the circuit. TEST the system for normal operation.
- No : GO to D6.
D3 CHECK CIRCUIT 29S-LE15 (OG/BK) OR CIRCUIT 29S-LE22 (OG/GN) FOR AN OPEN
- Key in OFF position.
- Disconnect: LH Headlamp C1021 or RH Headlamp C1041.
- Key in ON position.
- Measure the voltage between LH headlamp C1021-3, circuit 29S-LE15 (OG/BK), harness side and ground; or between RH headlamp C1041-3, circuit 29S-LE22 (OG/GN), harness side and ground.
  
  Fig 2: Measuring Voltage Between LH Headlamp C1021-3, Circuit 29S-LE15 (OG/BK) And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes : GO to D4.
- No : REPAIR the circuit. CLEAR the DTCs. TEST the system for normal operation.
D4 CHECK CIRCUIT 31S-LE15 (BK/GN) OR CIRCUIT 31S-LE22 (BK/RD) FOR AN OPEN
- Key in OFF position.
- Disconnect: FEM C201c.
- Measure the resistance between LH headlamp C1021-6, circuit 31S-LE15 (BK/GN), harness side and FEM C201a-17, circuit 31S-LE15 (BK/GN), harness side; or RH headlamp C1041-6, circuit 31S-LE22 (BK/RD), harness side and FEM C201a-10, circuit 31S-LE22 (BK/RD), harness side.
  
  Fig 3: Measuring Resistance Between LH Headlamp C1021-6, Circuit 31S-LE15 (BK/GN), Harness Side And FEM C201A-17, Circuit 31S-LE15
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
- Yes : GO to D5.
- No : REPAIR the circuit. CLEAR the DTCs. TEST the system for normal operation.
D5 CHECK THE HEADLAMP ASSEMBLY
- Key in OFF position.
- Connect: LH Headlamp C1021 or RH Headlamp C1041.
- Key in ON position.
- Connect a fused (10A) jumper wire between FEM C201a-17, circuit 31S-LE15 (OG/BK), harness side and ground; or between the FEM C201a-10, circuit 31S-LE22 (OG/GN), harness side and ground.
  
  Fig 4: Connecting Fused (10A) Jumper Wire Between FEM C201a-17, Circuit 31S-LE15 And Ground; Or Between The FEM C201a-10, Circuit 31S-LE22 And Ground
  Courtesy of FORD MOTOR CO.
- Does the inoperative headlamp now illuminate?
- Yes : GO to D6.
- No : REPAIR or INSTALL a new headlamp assembly. REFER to HEADLAMP ASSEMBLY in this article. CLEAR the DTCs. TEST the system for normal operation.
D6 CHECK FOR FEM OPERATION
- Key in OFF position.
- Disconnect all FEM connectors.
- Check for:
  - corrosion operation.
  - pushed-out pins
- Connect all FEM 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 FEM. REFER to MULTIFUNCTION ELECTRONIC MODULES . TEST the system for normal operation.
- No : The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.