Pinpoint Test E: The Low Beam(s) Are Always On
Headlamps
Pinpoint Test E: The Low Beam(s) Are Always On
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 to monitor the OFF, PARKING LAMPS ON and HEADLAMPS ON positions. At any given time, the headlamp switch routes one of the input circuits to ground.
When the SJB (Smart Junction Box) detects a concern with the headlamp switch input for 5 seconds (multiple headlamp switch inputs active at the same time or no inputs active), the SJB (Smart Junction Box) turns the exterior lamps on.
Halogen Headlamps
When the SJB (Smart Junction Box) detects the headlamp switch in the HEADLAMPS ON position, the SJB (Smart Junction Box) provides voltage to the headlamp relay coils. When the headlamp relay coils are energized, voltage is routed to the headlamps.
On vehicles equipped with Daytime Running Lamps (DRL), the DRL (Daytime Running Lamps) relay 1 also provides voltage to the low beam system when energized, passing through the headlamps in series to give the appearance of the lamps illuminated at a reduced intensity.
High Intensity Discharge (HID) Headlamps
When the SJB (Smart Junction Box) detects the headlamp switch in the HEADLAMPS ON position, the SJB (Smart Junction Box) provides voltage to the LH and RH ballasts.
The High Intensity Discharge (HID) headlamps utilize a second (hot at all times) voltage feed to the HID (High Intensity Discharge) ballasts.
When the ballasts are provided voltage from the SJB (Smart Junction Box), the ballasts provide high voltage to the HID (High Intensity Discharge) bulbs.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Headlamp relay
- Headlamp switch
- Ballast
- SJB (Smart Junction Box)
PINPOINT TEST E : THE LOW BEAM(S) ARE ALWAYS ON
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
E1 CHECK FOR AUTOLAMP DTCs
- Review the DTCs retrieved from the SJB (Smart Junction Box) self-test.
Is DTC B1696, B1791, B1793 or B2008 present?
Yes
GO to Pinpoint Test J Pinpoint Test J: The Autolamps Are On Continuously.
No
GO to E2.
E2 CHECK THE SJB (Smart Junction Box) AUTOLAMP ON REQUEST PID
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: SJB (Smart Junction Box) DataLogger.
- While placing the headlamp switch in the AUTOLAMPS ON and then OFF position, monitor the SJB (Smart Junction Box) 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 E3.
No
GO to Pinpoint Test J Pinpoint Test J: The Autolamps Are On Continuously.
E3 CHECK THE SJB (Smart Junction Box) HEADLAMP SWITCH PIDs
NOTE: Make sure the headlamp switch is lined up in the correct position when monitoring the PIDs.
NOTE: Only one PID should indicate ON at each headlamp switch position.
- Enter the following diagnostic mode on the scan tool: SJB (Smart Junction Box) DataLogger.
- While moving the headlamp switch through all positions, monitor the SJB (Smart Junction Box) 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)?
Yes
GO to E8.
No
GO to E4.
E4 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:
Are the voltages greater than 10 volts?
Yes
GO to E5.
No
GO to E6.
E5 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 . CLEAR the DTCs. REPEAT the self-test.
No
REPAIR circuit GD116 (BK/VT) for an open. CLEAR the DTCs. REPEAT the self-test.
E6 CHECK THE HEADLAMP SWITCH INPUT CIRCUITS FOR A SHORT TO GROUND
- Disconnect: SJB (Smart Junction Box) C2280B.
- Measure the resistance between the headlamp switch, harness side and ground as follows:
Are the resistances greater than 10,000 ohms?
Yes
GO to E7.
No
REPAIR the circuit in question for a short to ground. CLEAR the DTCs. REPEAT the self-test.
E7 CHECK THE HEADLAMP SWITCH INPUT CIRCUITS FOR AN OPEN
- Measure the resistance between the headlamp switch, harness side and the SJB (Smart Junction Box), harness side as follows:
Are the resistances less than 5 ohms?
Yes
GO to E14.
No
REPAIR the circuit in question for an open. CLEAR the DTCs. REPEAT the self-test.
E8 CHECK THE SJB (Smart Junction Box) OUTPUT
- Ignition OFF.
- Disconnect: SJB (Smart Junction Box) C2280E.
- Ignition ON.
Does the LH or RH headlamp continue to illuminate?
Yes
If equipped with HID (High Intensity Discharge) headlamps, GO to E9.
If both halogen headlamps are illuminated, GO to E10.
If one halogen headlamp is illuminated, GO to E12.
No
GO to E14.
E9 CHECK THE SJB (Smart Junction Box) LOW BEAM OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE (HID (High Intensity Discharge) HEADLAMPS)
- Ignition OFF.
- Disconnect: Illuminated Headlamp.
- Ignition ON.
- Measure the voltage between the LH headlamp C1021-8, circuit CLF04 (BN/BU), harness side and ground; or between the RH headlamp C1041-8, circuit CLF05 (BU/GN), harness side and ground.
Is any voltage present?
Yes
REPAIR circuit CLF04 (BN/BU) (LH headlamp) or circuit CLF05 (BU/GN) (RH headlamp) for a short to voltage. CLEAR the DTCs. REPEAT the self-test.
No
INSTALL a new ballast. REFER to Ballast . TEST the system for normal operation.
E10 ISOLATE THE DRL (Daytime Running Lamps) SYSTEM AS A CAUSE OF THE CONCERN
- Ignition OFF.
- Disconnect: RH Headlamp Relay.
- Ignition ON.
Does either headlamp continue to illuminate?
Yes
If the RH headlamp continues to illuminate, REPAIR circuit SBB25 (RD). TEST the system for normal operation.
If the LH headlamp continues to illuminate, GO to E11.
No
GO to Pinpoint Test X Pinpoint Test X: The Daytime Running Lamps (DRL) Are Always On.
E11 CHECK THE DRL (Daytime Running Lamps) CIRCUIT BETWEEN THE HEADLAMP RELAYS
- Ignition OFF.
- Disconnect: LH Headlamp Relay.
- Ignition ON.
Does the LH headlamp continue to illuminate?
Yes
REPAIR circuit SBB16 (VT/RD) between the LH headlamp relay and the LH headlamp for a short to voltage. TEST the system for normal operation.
No
REPAIR circuit SBB16 (VT/RD) between the headlamp relays for a short to voltage. TEST the system for normal operation.
E12 CHECK THE HEADLAMP RELAY OUTPUT
- Ignition OFF.
- Disconnect: Suspect Headlamp Relay.
- Ignition ON.
Does the headlamp continue to illuminate?
Yes
REPAIR circuit SBB16 (VT/RD) (LH headlamp) or circuit SBB25 (RD) (RH headlamp) for a short to voltage. TEST the system for normal operation.
No
GO to E13.
E13 CHECK THE HEADLAMP RELAY
- Substitute a known good relay for the headlamp relay in question.
Does the headlamp continue to illuminate?
Yes
REMOVE the known good relay. REPAIR circuit CLF04 (BN/BU) (LH headlamp) or circuit CLF05 (BU/GN) (RH headlamp) for a short to voltage. CLEAR the DTCs. REPEAT the self-test.
No
REMOVE the known good relay. INSTALL a new headlamp relay. TEST the system for normal operation.
E14 CHECK FOR CORRECT SJB (Smart Junction Box) OPERATION
- Disconnect all the SJB (Smart Junction Box) connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the SJB (Smart Junction Box) 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 (Smart Junction Box). 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.