Pinpoint Test D: The Low Beam(S) Are Always On
WARNING: This page is about a different car, the 2011 Mercury Milan, 2011 Lincoln MKZ, and 2011 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
- D1 CHECK FOR AUTOLAMP DTCs
- Review the DTCs retrieved from the SJB self-test.
- Is DTC B1696, B1791, B1793 or B2008 present?
- D2 CHECK THE SJB AUTOLAMP ON REQUEST PID
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: SJB DataLogger.
- While placing the headlamp switch in the AUTOLAMPS ON and then OFF position, monitor the SJB headlamp switch PID (HDLMP_AUT_CKT).
- Does the PID indicate ON with the headlamp switch in the AUTOLAMPS ON position and OFF when the headlamp switch is in the OFF position?
- Yes : GO to D3.
- No : GO to PINPOINT TEST H .
- D3 CHECK THE SJB HEADLAMP SWITCH PIDs NOTE: Make sure the headlamp switch is lined up in the correct position when monitoring the PIDs.
- Enter the following diagnostic mode on the scan tool: SJB DataLogger.
- While moving the headlamp switch through all positions, monitor the SJB headlamp switch input PIDs (HDLMP_OFF_CKT, HDLMP_PRK_CKT, HDLMP_ON_CKT).
- Do the headlamp switch positions agree with the PIDs (with only one PID indicating ON in each position)?
NOTE: Only one PID should indicate ON at each headlamp switch position.- Yes : GO to D8.
- No : GO to D4.
- D4 CHECK FOR VOLTAGE SIGNALS TO THE HEADLAMP SWITCH
- Ignition OFF.
- Disconnect: Headlamp Switch C205.
- Measure the voltage between the headlamp switch, harness side and ground as follows:HEADLAMP SWITCH CONNECTOR-PIN REFERENCE TABLE
Headlamp Switch Connector-Pin Circuit C205-6 CLF23 (WH/VT) C205-2 CLS34 (GY) C205-7 CLF18 (BU/WH) - Are the voltages greater than 10 volts?
- Yes : GO to D5.
- No : GO to D6.
- D5 CHECK FOR VOLTAGE TO THE HEADLAMP SWITCH USING THE CONNECTOR GROUND
- Measure the voltage between the headlamp switch C205-6, circuit CLF23 (WH/VT), harness side and the headlamp switch C205-3, circuit GD116 (BK/VT), harness side.
- Is the voltage greater than 10 volts?
- Yes : INSTALL a new headlamp switch. REFER to HEADLAMP SWITCH in this service information. TEST the system for normal operation.
- No : REPAIR circuit GD116 (BK/VT) for an open. TEST the system for normal operation.
- D6 CHECK THE HEADLAMP SWITCH INPUT CIRCUITS FOR A SHORT TO GROUND
- Disconnect: SJB C2280b.
- Measure the resistance between the headlamp switch, harness side and ground as follows:HEADLAMP SWITCH CONNECTOR-PIN REFERENCE TABLE
Headlamp Switch Connector-Pin Circuit C205-6 CLF23 (WH/VT) C205-2 CLS34 (GY) C205-7 CLF18 (BU/WH) - Are the resistances greater than 10,000 ohms?
- Yes : GO to D7.
- No : REPAIR the circuit in question for a short to ground. TEST the system for normal operation.
- D7 CHECK THE HEADLAMP SWITCH INPUT CIRCUITS FOR AN OPEN
- Measure the resistance between the headlamp switch, harness side and the SJB, harness side as follows:CONNECTOR PIN REFERENCE TABLE
Headlamp Switch Connector-Pin SJB Connector-Pin Circuit C205-6 C2280b-47 CLF23 (WH/VT) C205-2 C2280b-31 CLF34 (YE/OG) C205-7 C2280b-30 CLF18 (BU/WH) - Are the resistances less than 5 ohms?
- Yes : GO to D11.
- No : REPAIR the circuit in question for an open. TEST the system for normal operation.
- Measure the resistance between the headlamp switch, harness side and the SJB, harness side as follows:
- D8 CHECK THE SJB OUTPUT
- Disconnect: SJB C2280e.
- Does the LH or RH headlamp continue to illuminate?
- Yes
: For MKZ with halogen headlamps or Fusion, REPAIR circuit CLF04 (BN/BU) (LH headlamp) or circuit CLF05 (BU/GN) (RH headlamp) for a short to voltage. TEST the system for normal operation.
For MKZ with HID headlamps or Milan, GO to D9.
- No : GO to D11.
- D9 CHECK THE HEADLAMP RELAY OUTPUT CIRCUIT
- Disconnect: Suspect Headlamp Relay.
- Does the LH or RH headlamp continue to illuminate?
- Yes : REPAIR circuit CLF30 (VT/BN) (LH headlamp) or circuit CLF31 (YE/GY) (RH headlamp) for a short to voltage. TEST the system for normal operation.
- No : GO to D10.
- D10 CHECK HEADLAMP RELAY
- Substitute a known good relay.
- Does the LH or RH headlamp continue to illuminate?
- Yes : REMOVE the known good relay. TEST the system for normal operation.
- No : REMOVE the known good relay. GO to D11.
- D11 CHECK FOR CORRECT SJB OPERATION
- Disconnect all the SJB connectors.
- Check for:
- corrosion
- damaged pins
- 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 MULTIFUNCTION ELECTRONIC MODULES -- FUSION, MILAN & MKZ article. 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.