Headlights turn off while driving

Hi,

When this happens, do you lose both high and low beam lights? Also, I need to know if you have daytime running lights (DRL). The wiring schematics are different.

I went through the schematic for a vehicle with DRL. Here is my theory at this point.

The U codes you have are related to the can-bus circuit. CAN stands for controller area network. Basically, all the modules are tied together via a few wires and communicate with each other.

The can-bus is what signals a CPU in the intelligent power distribution (IPDM) box under the hood to energize the headlamps' high and low beams. Each selection has a relay to power the lights. Since the codes indicate an issue within the can-bus, I feel there is a breakdown in the communication between the body control module (BCM) and the IPDM. I suspect there is a faulty connection either at the BCM or the IPDM.

If you look at the attached pics, they provide the wiring schematic related to the headlamps and the can-bus. I highlighted the two wires from the CAN, one is yellow, and one is blue. What I suggest is to locate these at the BCM and the IPDM and confirm they are in good condition and not corroded or damaged in any way.

The BCM is under the dash on the left side of the vehicle and the IPDM is under the hood where the fuses and relays are located.

Let me know what you find or if you have other questions.

Take care,

Joe

See pic below.

Hi,

It sounds like one of the relays is failing. Have you been able to test them? I rechecked the schematics and power is supplied to the relays from the ignition switch, so a faulty relay is my first suspect.

Let me know.

Joe

See pic below for relay location.