B2473

DTC B2473 High Beam Fault:

CIRCUIT DESCRIPTION
When the Body Control Module (BCM) receives an input to turn the high beam lamps On, it grounds both high beam headlamp relay coils at terminal C8 energizing the relays. This places both high beam headlamps, that were in a series circuit, in a parallel circuit by providing a separate ground path for each headlamp. This configuration allows the high beam headlamps to illuminate at full intensity.

CONDITIONS FOR SETTING THE DTC
The BCM monitors output to the high beam relays every second at terminal C8. The fault code is set when the commanded state doesn't match the feedback for 2 seconds (open or short to ground in CKT M60).

ACTION TAKEN WHEN THE DTC SETS
^ The BCM continues to command the state requested until it is achieved or until it changes.
^ Stores a DTC B2473 in the BCM memory.

CONDITIONS FOR CLEARING THE DTC
^ The conditions for the fault are no longer present.
^ The use of a scan tool.
^ A history DTC will clear after 50 ignition cycles if the condition for the fault is no longer present.

DIAGNOSTIC AIDS
^ The problem may be intermittent if the DTC is a history DTC. Try performing the tests shown while wiggling the wiring and the connectors. Wiggling the wiring and the connectors can often cause the malfunction to appear. Refer to Intermittents and Poor Connections. Intermittents and Poor Connections
^ A short to ground in circuit M6O may cause the High Beam indicator bulb, located in the instrument cluster, along with the RH high beam headlamp to illuminate at all times.

TEST DESCRIPTION
The following numbers refer to the step numbers on the diagnostic table:
2. When the high beam relays are commanded On and Off the status should match the commanded state. In most cases a no change in status indicates a circuit problem.
3. This test checks for proper voltage and ground input to the BCM. Check the BCM again after checking the voltage and ground inputs to the BCM to see if the DTC resets, indicating an internal failure.