Pinpoint Test B: One Or Both High Beams Are Inoperative
Headlamps
Pinpoint Test B: One or Both High Beams are Inoperative
Refer to Wiring Diagram Set 85, Headlamps/Autolamps for schematic and connector information Electrical Diagrams.
Normal Operation
The Steering Column Control Module (SCCM) monitors input from the multifunction switch. When the headlamps are on and the multifunction switch is placed in the HIGH BEAM position, the SCCM (Steering Column Control Module) sends a message over the High Speed Controller Area Network (HS-CAN) to the Body Control Module (BCM), indicating a high beam request. The BCM (Body Control Module) then provides voltage to the high beam shutters within the headlamp assemblies.
The BCM (Body Control Module) provides an overload protection of the high beam output circuits. When an excessive current draw is detected, the BCM (Body Control Module) disables the affected high beam circuit driver.
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- Multifunction switch
- Headlamp assembly
- SCCM (Steering Column Control Module)
- BCM (Body Control Module)
PINPOINT TEST B : ONE OR BOTH HIGH BEAMS ARE INOPERATIVE
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
B1 CHECK THE LOW BEAM OPERATION
- Ignition OFF.
- Place the headlamp switch in the HEADLAMPS ON position.
Do the low beams illuminate?
Yes
If an individual high beam is inoperative, GO to B3.
If both high beams are inoperative, VERIFY the BCM (Body Control Module) fuse 39 (15A) is OK. If OK, GO to B2. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short Electrical Diagrams.
If no DTCs are present, TEST the system for normal operation.
If DTC U1000:00 is present, CLEAR the DTCs and REPEAT the self-test (required to enable the high beam output driver if DTC U1000:00 is present). TEST the system for normal operation.
If DTC U3000:49 is present, INSTALL a new BCM (Body Control Module). TEST the system for normal operation.
No
GO to Pinpoint Test A Pinpoint Test A: One Or Both Low Beams Are Inoperative.
B2 CHECK THE MULTIFUNCTION SWITCH INPUT
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: SCCM (Steering Column Control Module) DataLogger.
- Monitor the SCCM (Steering Column Control Module) multifunction switch flash-to-pass and high beam PIDs (FLASH-to-PASS, HEADLAMP_SW) while placing the multifunction switch in the FLASH-TO-PASS and HIGH BEAM positions.
Do the PID values agree with the multifunction switch position?
Yes
GO to B8.
No
INSTALL a new multifunction switch. TEST the system for normal operation.
If the concern still exists, INSTALL an new SCCM (Steering Column Control Module). TEST the system for normal operation.
B3 CHECK FOR VOLTAGE TO THE HEADLAMP
- Place the headlamp switch in the OFF position.
- Disconnect: Inoperative Headlamp.
- Place the headlamp switch in the HEADLAMPS ON position and the multifunction switch in the HIGH BEAM position.
- Measure the voltage between the LH headlamp C1021A-3, circuit CLF02 (GY/BN), harness side and ground; or between the RH headlamp C1041A-3, circuit CLF03 (VT/OG), harness side and ground.
Is the voltage greater than 10 volts?
Yes
GO to B4.
No
GO to B5.
B4 CHECK THE HEADLAMP GROUND CIRCUIT FOR AN OPEN
- Measure the voltage between the LH headlamp C1021A-3, circuit CLF02 (GY/BN), harness side and the LH headlamp C1021A-6, circuit GD120 (BK/GN), harness side; or between the RH headlamp C1041A-3, circuit CLF03 (VT/OG), harness side and the RH headlamp C1041A-6, circuit GD123 (BK/GY), harness side.
Is the voltage greater than 10 volts?
Yes
INSTALL a new headlamp assembly. REFER to Headlamp Assembly . TEST the system for normal operation.
No
REPAIR circuit GD120 (BK/GN) (LH headlamp) or circuit GD123 (BK/GY) (RH headlamp) for an open. TEST the system for normal operation.
B5 REPEAT THE ON-DEMAND SELF-TEST AND CHECK FOR VOLTAGE TO THE HEADLAMP
- Place the headlamp switch in the OFF position.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: BCM (Body Control Module) Self-Test.
- Clear the DTCs and carry out the on-demand self-test.
- Place the headlamp switch in the HEADLAMPS ON position and the multifunction switch in the HIGH BEAM position.
- Measure the voltage between the LH headlamp C1021A-3, circuit CLF02 (GY/BN), harness side and ground; or between the RH headlamp C1041A-3, circuit CLF03 (VT/OG), harness side and ground.
Is the voltage greater than 10 volts?
Yes
INSTALL a new headlamp assembly. REFER to Headlamp Assembly . TEST the system for normal operation.
No
GO to B6.
B6 CHECK THE BCM (Body Control Module) HIGH BEAM VOLTAGE SUPPLY CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: BCM (Body Control Module) C2280E.
- Measure the resistance between the LH headlamp C1021A-3, circuit CLF02 (GY/BN), harness side and ground; or between the RH headlamp C1041A-3, circuit CLF03 (VT/OG), harness side and ground.
Is the resistance greater than 10,000 ohms?
Yes
GO to B7.
No
REPAIR the circuit in question for a short to ground. After the repair:
If no DTCs are present, TEST the system for normal operation.
If DTC U1000:00 is present, CLEAR the DTCs and REPEAT the self-test (required to enable the low beam output driver if DTC U1000:00 is present). TEST the system for normal operation.
If DTC U3000:49 is present, INSTALL a new BCM (Body Control Module). TEST the system for normal operation.
B7 CHECK THE BCM (Body Control Module) HIGH BEAM VOLTAGE SUPPLY CIRCUIT FOR AN OPEN
- Measure the resistance between the LH headlamp C1021A-3, circuit CLF02 (GY/BN), harness side and the BCM (Body Control Module) C2280E-8, circuit CLF02 (GY/BN), harness side; or between the RH headlamp C1041A-3, circuit CLF03 (VT/OG), harness side and the BCM (Body Control Module) C2280E-7, circuit CLF03 (VT/OG), harness side.
Is the resistance less than 5 ohms?
Yes
GO to B8.
No
REPAIR circuit CLF02 (GY/BN) (LH headlamp) or circuit CLF03 (VT/OG) (RH headlamp) for an open. TEST the system for normal operation.
B8 CHECK FOR CORRECT BCM (Body Control Module) OPERATION
- Disconnect all the BCM (Body Control Module) connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the BCM (Body Control Module) 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 BCM (Body Control Module). 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.