Pinpoint Test D: The Headlamps Are On Continuously
Headlamps
Pinpoint Tests
Pinpoint Test D: The Headlamps Are On Continuously
Refer to Wiring Diagram Set 85, Headlamps/Autolamps for schematic and connector information. Diagrams By Number
Normal Operation
The Smart Junction Box (SJB) sends reference signals to the headlamp switch through circuits CLF18 (BU/WH), CLF19 (VT/GN), CLF23 (WH/VT) and CLS34 (GY). When the headlamp switch is placed in the HEADLAMPS ON position, the voltage signal is routed to ground through circuit GD145 (BK/BU). If the SJB detects a fault with the headlamp switch inputs, the SJB turns the exterior lamps on by default.
When the SJB detects the headlamp switch in the HEADLAMPS ON position and the multifunction switch in the LOW BEAM position, the SJB sends voltage through circuits CLF04 (BN/BU) (LH headlamp) and CLF05 (BU/GN) (RH headlamp) to the low beam headlamps.
When the SJB detects the headlamp switch in the HEADLAMPS ON position and the multifunction switch in the HIGH BEAM position, the SJB sends voltage through circuits CLF02 (GY/BN) (LH headlamp) and CLF03 (VT/OG) (RH headlamp) to the high beam headlamps.
The SJB sends a reference signal to the multifunction switch through circuits CLF27 (GN/BN) and CLF17 (WH/OG). When the multifunction switch is placed in the FLASH-TO-PASS or HIGH BEAM position, the voltage signal is routed to ground. When the SJB detects a request for the flash-to-pass, the SJB sends voltage to the high beam headlamps.
B1472-B2507:
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Headlamp switch
- Multifunction switch
- SJB
PINPOINT TEST D: THE HEADLAMPS ARE ON CONTINUOUSLY
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
NOTE: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to Battery.
-------------------------------------------------
D1 VERIFY THE HEADLAMP OPERATION
- Ignition ON.
- Make sure the headlamp switch is in the OFF position and the multifunction switch is in the LOW BEAM position.
- Are the low beam headlamps illuminated?
Yes
GO to D2.
No
GO to D9.
-------------------------------------------------
D2 CHECK FOR AUTOLAMP DTCs
- Check the recorded DTCs from the SJB self-test.
- Is DTC B1696, B1791, B1793 or B2008 recorded?
Yes
REFER to DTC Charts. [1][2]Diagnostic Trouble Code Descriptions
No
GO to D3.
-------------------------------------------------
D3 CHECK THE SJB HEADLAMP SWITCH PID
- Enter the following diagnostic mode on the scan tool: SJB DataLogger.
- Monitor the SJB headlamp switch PIDs (P_LMP_SW, HEAD_L) while moving the headlamp switch through all positions.
- Do the headlamp switch positions agree with the PIDs?
Yes
GO to D8.
No
GO to D4.
-------------------------------------------------
D4 CHECK THE HEADLAMP SWITCH
- Ignition OFF.
- Disconnect: Headlamp Switch C205.
- Carry out the headlamp switch component test.
- Is the headlamp switch OK?
Yes
GO to D5.
No
INSTALL a new headlamp switch. REFER to Headlamp Switch Service and Repair. CLEAR the DTCs. REPEAT the self-test.
-------------------------------------------------
D5 CHECK CIRCUIT GD145 (BK/BU) FOR AN OPEN
- Disconnect: Negative Battery Cable.
- Measure the resistance between the headlamp switch C205-7, circuit GD145 (BK/BU), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
GO to D6.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
-------------------------------------------------
D6 CHECK THE HEADLAMP SWITCH INPUT CIRCUIT FOR A SHORT TO GROUND
- Disconnect: SJB C2280d.
- Measure the resistance between the headlamp switch C205-10, circuit CLF18 (BU/WH), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to D7.
No
REPAIR circuit CLF18 (BU/WH) for an open. CLEAR the DTCs. REPEAT the self-test.
-------------------------------------------------
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:
- Are the resistances less than 5 ohms?
Yes
GO to D13.
No
REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.
-------------------------------------------------
D8 CHECK CIRCUITS CLF04 (BN/BU) (LH HEADLAMP) AND CLF05 (BU/GN) (RH HEADLAMP) FOR A SHORT TO VOLTAGE
- Disconnect: SJB C2280e.
- Does the LH or RH headlamp continue to illuminate?
Yes
REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.
No
GO to D13.
-------------------------------------------------
D9 CHECK THE SJB MULTIFUNCTION SWITCH PIDs
- Enter the following diagnostic mode on the scan tool: SJB DataLogger.
- NOTE: Make sure the multifunction switch is in the NEUTRAL position.
- Monitor the SJB high beam and flash-to-pass PIDs (HBEAMSW, Pass).
- Do the PIDs indicate the multifunction switch HIGH BEAM or FLASH-TO-PASS position is active?
Yes
GO to D10.
No
GO to D12.
-------------------------------------------------
D10 CHECK THE MULTIFUNCTION SWITCH
- Ignition OFF.
- Disconnect: Multifunction Switch C202.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: SJB DataLogger.
- Monitor the SJB high beam and flash-to-pass PIDs (HBEAMSW, Pass).
- Do the PIDs indicate the multifunction switch HIGH BEAM or FLASH-TO-PASS position is active?
Yes
GO to D11.
No
INSTALL a new multifunction switch. CLEAR the DTCs. REPEAT the self-test.
-------------------------------------------------
D11 CHECK CIRCUIT CLF17 (WH/OG) (HIGH BEAM) AND CIRCUIT CLF27 (GN/BN) (FLASH-TO-PASS) FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: SJB C2280d.
- Measure the resistance between the multifunction switch C202-6, circuit CLF17 (WH/OG), harness side and ground; and between the multifunction switch C202-4, circuit CLF27 (GN/BN), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to D13.
No
REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.
-------------------------------------------------
D12 CHECK CIRCUITS CLF02 (GY/BN) (LH HEADLAMP) AND CLF03 (VT/OG) FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: SJB C2280e.
- Ignition ON.
- Does the LH or RH headlamp continue to illuminate?
Yes
REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.
No
GO to D13.
-------------------------------------------------
D13 CHECK FOR CORRECT SJB OPERATION
- Ignition OFF.
- 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. 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.
-------------------------------------------------