Pinpoint Test D: One Low Beam Headlamp Is Inoperative

WARNING: This page is about a different car, the 2006 Mercury Mariner and 2006 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.

D1 CHECK CIRCUIT 57 (BK) FOR AN OPEN

Key in OFF position.
Disconnect: Inoperative Headlamp.

Measure the resistance between the inoperative headlamp, harness side and ground as follows:

INOPERATIVE HEADLAMP CONNECTOR AND CIRCUIT REFERENCE

Inoperative Headlamp	Connector-Pin (Escape)	Connector-Pin (Mariner)	Circuit
LH headlamp	C1021-4	C1284-2	57 (BK)
RH headlamp	C1041-4	C1285-2	57 (BK)

Is the resistance less than 5 ohms?

Yes: GO to D2.

No: REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.

D2 CHECK CIRCUIT 160 (DB/WH) (LH HEADLAMP) OR CIRCUIT 161 (DG/OG) (RH HEADLAMP) FOR VOLTAGE

Key in ON position.
Place the multifunction switch in the headlamps ON position.

Measure the voltage between the inoperative headlamp, harness side and ground as follows:

INOPERATIVE HEADLAMP CONNECTOR AND CIRCUIT REFERENCE

Inoperative Headlamp	Connector-Pin (Escape)	Connector-Pin (Mariner)	Circuit
LH headlamp	C1021-7	C1284-1	160 (DB/WH)
RH headlamp	C1041-7	C1285-1	161 (DG/OG)

Is the voltage greater than 10 volts?

Yes: REPAIR or INSTALL a new headlamp. CLEAR the DTCs. REPEAT the self-test.

No: GO to D3.

D3 CHECK CIRCUIT 160 (DB/WH) (LH HEADLAMP) OR CIRCUIT 161 (DG/OG) (RH HEADLAMP) FOR AN OPEN

Key in OFF position.
Place the multifunction switch in the OFF position.
Disconnect: SJB C2280b.

Measure the resistance between the inoperative headlamp, harness side and the SJB, harness side as follows:

INOPERATIVE HEADLAMP AND SJB CONNECTOR AND CIRCUIT REFERENCE

Inoperative Headlamp	Connector-Pin (Escape)	Connector-Pin (Mariner)	SJB Connector-Pin	Circuit
LH headlamp	C1021-7	C1284-1	C2280b-22	160 (DB/WH)
RH headlamp	C1041-7	C1285-1	C2280b-26	161 (DG/OG)

Is the resistance less than 5 ohms?

Yes: GO to D4.

No: REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.

D4 CHECK CIRCUIT 160 (DB/WH) (LH HEADLAMP) OR CIRCUIT 161 (DG/OG) (RH HEADLAMP) FOR A SHORT TO GROUND

Measure the resistance between the inoperative headlamp, harness side and ground as follows:

INOPERATIVE HEADLAMP CONNECTOR AND CIRCUIT REFERENCE

Inoperative Headlamp	Connector-Pin (Escape)	Connector-Pin (Mariner)	Circuit
LH headlamp	C1021-7	C1284-1	160 (DB/WH)
RH headlamp	C1041-7	C1285-1	161 (DG/OG)

Is the resistance greater than 10,000 ohms?

Yes: GO to D5.

No: REPAIR the circuit in question. RUN the on-demand self-test (required to clear certain DTCs). CORRECT any unresolved DTCs. CLEAR all DTCs. TEST the system for normal operation.

D5 CHECK FOR CORRECT SJB OPERATION
- Disconnect all the SJB connectors.
- Check for:
  - corrosion
  - pushed-out pins
- Connect all the SJB 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 SJB. REFER to SMART JUNCTION BOX (SJB) . TEST the system for normal operation.

No: The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.