B2470

DTC B2470 Daytime Running Lamps Fault:

DTC B2470 Daytime Running Lamps Fault (Part 1 Of 2):

DTC B2470 Daytime Running Lamps Fault (Part 2 Of 2):

CIRCUIT DESCRIPTION
The Body Control Module (BCM) commands the daytime running lamps (DRL) On and Off through a discrete output to the DRL relay. The daytime running lamps can only be active under one or all of the following conditions:
^ The ignition switch is in the On position.
^ The Twilight Sentinel is not active.
^ The low beam head lamps are Off.
^ The high beam headlamps are Off.
^ The fog lamps are Off.
^ The transmission is not in PARK.

The high beam lamps are placed in series when the DRL relay is energized. This circuit configuration provides the lower illumination for the DRL.

CONDITIONS FOR SETTING THE DTC
The BCM monitors the output to the DRL relay every second at terminal C5. The fault code is set when the feedback doesn't match the commanded state for 2 seconds (open circuit, short to B+ or ground).

ACTION TAKEN WHEN THE DTC SETS
^ The BCM continues to command the state requested until it is achieved or changes.
^ Stores a DTC B2470 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 consecutive ignition cycles if the condition for the fault is no longer present.

DIAGNOSTIC AIDS
^ Refer to Fuse Block Details for an end view and for terminal assignments of the relay box when the diagnostics directs you to take electrical measurements at the relay box.
^ 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

TEST DESCRIPTION
The following numbers refer to the step numbers on the diagnostic table:
2. When the DRL relay is commanded On/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 see if the DTC resets, indicating an internal failure.
10. The relay may be faulty if no circuit problems are verified. However, in most cases this is an unlikely failure.