B2473

CIRCUIT DESCRIPTION
The rear fuse block supplies battery positive voltage to the HIGH/LOW BEAM HEADLAMP relay coil. The Body Control Module (BCM) provides ground to the HIGH/LOW BEAM HEADLAMP relay in the control circuit. The BCM monitors the voltage in the HIGH/LOW BEAM HEADLAMP relay control circuit every second.

CONDITIONS FOR RUNNING THE DTC
A short to ground in the HIGH/LOW BEAM HEADLAMP relay control circuit will be tested when the following conditions are met:
^ The ignition is ON.
^ The HIGH/LOW BEAM HEADLAMP relay is de-energized.

A short to battery positive voltage in the HIGH/LOW BEAM HEADLAMP relay control circuit will be tested when the following conditions are met:
^ The ignition is ON.
^ The HIGH/LOW BEAM HEADLAMP relay is energized.

CONDITIONS FOR SETTING THE DTC
One of the following conditions will cause this DTC to set:
^ The HIGH/LOW BEAM HEADLAMP relay is de-energized, and the BCM detects that the voltage in the control circuit of the HIGH/LOW BEAM HEADLAMP relay is low for at least 2 seconds.
^ The HIGH/LOW BEAM HEADLAMP relay is energized, and the BCM detects that the control circuit of the HIGH/LOW BEAM HEADLAMP relay is high for at least 2 seconds.

ACTION TAKEN WHEN THE DTC SETS
The BCM turns OFF the HIGH/LOW BEAM HEADLAMP relay output, until the condition for setting the DTC is no longer present.

CONDITIONS FOR CLEARING THE DTC
The DTC will clear when the following conditions are met:
^ The BCM detects that the voltage in the control circuit of the HIGH/LOW BEAM HEADLAMP relay is no longer low for at least 2 seconds.
^ The BCM detects that the control circuit of the HIGH/LOW BEAM HEADLAMP relay is no longer high for at least 2 seconds.

TEST DESCRIPTION

Steps 1-13:

The number(s) below refer to the step number(s) on the diagnostic table.
2. Listen for an audible click when the HIGH/LOW BEAM HEADLAMP relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
3. Tests for voltage at the coil side of the HIGH/LOW BEAM HEADLAMP relay. The RADIO/PHONE fuse supplies power to the coil side of the HIGH/LOW BEAM HEADLAMP relay.
4. Verifies that the BCM is providing ground to the HIGH/LOW BEAM HEADLAMP relay.
5. Tests if ground is constantly being applied to the HIGH/LOW BEAM HEADLAMP relay.