Pinpoint Test B: The Automatic High Beam Feature Is Inoperative
Headlamps
Pinpoint Tests
Pinpoint Test B: The Automatic High Beam Feature Is Inoperative
Refer to Wiring Diagram Set 11, Fuse and Relay Information for schematic and connector information. Diagrams By Number
Refer to Wiring Diagram Set 85, Headlamps/Autolamps for schematic and connector information. Diagrams By Number
NOTE: The Headlamp Control Module 2 (HCM-2) is also known as the automatic high beam control module.
Normal Operation
The HCM-2 controls the automatic high beam feature when active. The HCM-2 turns the high beam headlamps on when the following conditions are met:
- The feature has been enabled using the message center
- The autolamps feature has turned the exterior lamps on
- The fog lamps are off
- The vehicle speed is greater than 51 km/h (32 mph)
- The HCM-2 determines the ambient lighting conditions are dark enough
- The HCM-2 does not detect any light source that can be interpreted as an illuminated vehicle lamp
The HCM-2 turns the high beams off if any of the following occur:
- The HCM-2 detects any light source that can be interpreted as an illuminated vehicle lamp
- The HCM-2 determines the ambient lighting conditions are not dark enough
- The vehicle speed falls below 44 km/h (27 mph)
- The fog lamps are turned on
- The autolamps are turned off
- The HCM-2 determines the view is blocked
When the HCM-2 determines that the high beams need to be turned on, the HCM-2 provides voltage to the coil side of the automatic high beam control relay. Battery voltage is supplied from the Battery Junction Box (BJB) fuse 15 (15A) to the switched side of the relay. When the relay is energized, voltage is routed to the headlamps.
The HCM-2 defaults to the low beams when the following DTCs are present:
- B11C7:15
- B11C7:46
- B11C7:97
- B11C8:11
- U1000:11
- U3000:11
The HCM-2 sets a DTC if any fault exists with the automatic high beam control relay coil circuits.
Field-Effect Transistor (FET) Protection
The HCM-2 FET protection utilizes a strategy similar to the SJB. The protected output circuit for the automatic high beam system is for the automatic high beam control relay output circuit.
This pinpoint test is intended to diagnose the following:
- Windshield debris
- Fuse
- Wiring, terminals or connectors
- Automatic high beam control relay
- HCM-2
PINPOINT TEST B: THE AUTOMATIC HIGH BEAM FEATURE IS INOPERATIVE
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
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B1 USE THE RECORDED DTCs FROM THE HCM-2 SELF-TEST
- Ignition OFF.
- Check the recorded results from the HCM-2 self-test.
- Are any DTCs present?
Yes
For DTC B11C7:97, GO to Pinpoint Test H. Pinpoint Test H: B11C7:97
For DTC B11C7:15, GO to B4.
For DTC B11C8:11, U1000:11 or U3000:11, GO to B7.
For all other HCM-2 DTCs, REFER to Diagnostic Trouble Code (DTC) Chart Testing and Inspection.
No
GO to B2.
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B2 CHECK THE VOLTAGE SUPPLY TO THE AUTOMATIC HIGH BEAM CONTROL RELAY
- Disconnect: Automatic High Beam Control Relay.
- Measure the voltage between the automatic high beam control relay pin 5, circuit SBB15 (WH/RD), BJB face side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to B3.
No
VERIFY the BJB fuse 15 (15A) is OK. If OK, REPAIR circuit SBB15 (WH/RD) for an open. TEST the system for normal operation. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. Diagrams By Number
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B3 CHECK THE AUTOMATIC HIGH BEAM CONTROL RELAY OUTPUT CIRCUIT FOR AN OPEN
- Place the headlamp switch in the HEADLAMPS ON position.
- Place the multifunction switch in the HIGH BEAM position.
- Measure the voltage between the automatic high beam control relay pin 3, circuit CLF08 (YE/VT), BJB face side and ground.
- Is the voltage greater than 10 volts?
Yes
INSTALL a new automatic high beam control relay. TEST the system for normal operation.
No
REPAIR circuit CLF08 (YE/VT) for an open. TEST the system for normal operation.
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B4 BYPASS THE HCM-2 (DTC B11C7:15)
- Disconnect: Inline C913.
- Connect a fused jumper wire between the headliner harness inline C913-A, circuit CBP35 (YE/GY), harness side and the inline C913-B, circuit CLF54 (BN/GN), harness side.
- NOTE: Make sure the multifunction switch is in the LOW BEAM position.
- Place the headlamp switch in the HEADLAMPS ON position.
- Ignition ON.
- Do the high beams illuminate?
Yes
REMOVE the jumper wire. INSTALL a new HCM-2. REFER to Headlamp Control Module 2 (HCM-2) Headlamp Control Module 2 (HCM-2). CLEAR the DTCs.
REPEAT the self-test.
No
LEAVE the jumper wire connected. GO to B5.
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B5 CHECK THE AUTOMATIC HIGH BEAM CONTROL RELAY COIL CONTROL CIRCUIT FOR AN OPEN
- Place the headlamp switch in the OFF position.
- Disconnect: Automatic High Beam Control Relay.
- Measure the voltage between the automatic high beam control relay pin 2, circuit CLF54 (BN/GN),BJB face side and ground.
- Is the voltage greater than 10 volts?
Yes
LEAVE the jumper wire connected. GO to B6.
No
REMOVE the jumper wire. REPAIR circuit CLF54 (BN/GN) for an open. CLEAR the DTCs. REPEAT the self-test.
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B6 CHECK THE AUTOMATIC HIGH BEAM CONTROL RELAY
- Substitute a known good relay.
- Place the headlamp switch in the HEADLAMPS ON position.
- Do the high beams illuminate?
Yes
REMOVE the jumper wire. INSTALL a new automatic high beam control relay. CLEAR the DTCs. REPEAT the self-test.
No
REMOVE the jumper wire. REPAIR circuit GD120 (BK/GN). CLEAR the DTCs. REPEAT the self-test.
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B7 CHECK THE AUTOMATIC HIGH BEAM CONTROL RELAY FOR A SHORT TO GROUND
- Disconnect: Automatic High Beam Control Relay.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: HCM-2 Self-Test.
- NOTE: DTC B11C7:15 may be present and should be ignored.
- Clear the DTCs and repeat the self-test (required to enable the automatic high beam control relay output driver if DTC U1000:11 is present).
- Is DTC B11C8:11 still present?
Yes
GO to B8.
No
INSTALL a new automatic high beam control relay. CLEAR the DTCs. REPEAT the self-test.
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B8 CHECK THE AUTOMATIC HIGH BEAM CONTROL RELAY COIL CONTROL CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: Inline C913.
- Measure the resistance between the automatic high beam control relay pin 2, circuit CLF54 (BN/GN), BJB face side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
INSTALL a new HCM-2. REFER to Headlamp Control Module 2 (HCM-2) Headlamp Control Module 2 (HCM-2). TEST the system for normal operation.
No
REPAIR circuit CLF54 (BN/GN) for a short to ground.
If DTC B11C8:11 is present, CLEAR the DTCs and REPEAT the on-demand self-test (required to enable the automatic high beam control relay output driver if DTC U1000:11 is present).
If DTC U3000:11 is present, INSTALL a new HCM-2. REFER to Headlamp Control Module 2 (HCM-2) Headlamp Control Module 2 (HCM-2). TEST the system for normal operation.
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