The largest online repair guide library for every car

About us
Contact support
FAQ
Sign up
Sign in

Intermittent Headlight Flicker & Tail Light Malfunction - 2016 435i Gran Coupe

0

Mike T. · rep 0 · May 25, 3:00 AM · 1 replies · solved · Question

Vehicle: 2016 BMW 435i Gran Coupe

I'm having some weird electrical issues with my 2016 BMW 435i Gran Coupe. The driver's side headlight occasionally flickers, especially over bumps, and sometimes it just goes out for a few seconds before coming back on.

Also, I've had a "Rear Right Tail Light Malfunction" warning pop up a couple of times on the dash, but when I check, the light seems to be working fine. It's very intermittent. Could this be a loose connection, or something more serious with a control module? It's really concerning, especially with the headlight.

✓ Accepted solution

ClearTheCode Admin

ClearTheCode Team · rep 0 · May 25, 3:00 AM

0

ClearTheCode admin answer:

Intermittent headlight flickering and tail light malfunction warnings in your 2016 BMW 435i Gran Coupe often point to issues within the vehicle's complex lighting control system.

Common Causes & Diagnostics:

  1. Loose Connections/Wiring Harness: The most straightforward cause. Vibrations (like driving over bumps) can temporarily break contact in a loose connector or a damaged wire. Inspect the wiring and connectors leading to the affected headlight and tail light assemblies.
  2. Faulty Bulb/LED Module: While the light might appear to work sometimes, an internal fault in the bulb (if xenon/halogen) or the LED driver module (common for modern BMWs) can cause flickering or intermittent failure. The tail light warning could be due to a failing resistor or LED segment.
  3. Footwell Module (FRM) or Lighting Control Module: In BMWs, the FRM (or similar lighting control module in newer models) manages many body electrical functions, including exterior lighting. A fault within this module can cause erratic light behavior and false warnings. Water intrusion can also damage these modules.
  4. Grounding Issues: Poor grounding for a specific circuit can lead to intermittent electrical problems. Check ground points near the affected lights.

When to See a Shop: While inspecting visible wiring and connections can be a DIY step, diagnosing module faults or tracing intermittent electrical issues requires specialized tools. If you're seeing B-codes (Body codes) related to lighting circuits or if the problem persists after checking basic connections, it's advisable to take your car to a BMW specialist. They can use diagnostic software to:

  • Read specific fault codes from the FRM or lighting modules.
  • Test individual lighting circuits and components.
  • Determine if a module replacement or software update is necessary. This is crucial as module replacement often requires coding to the vehicle.
Menu

Help & account