CAS FAULT CODE 8042C6 Ambient light 1 has short circuit

Ace Rimmer · 11-11-2020, 01:52 PM

I have this issue happening today, CAS fault code 8042C6.
Got into the car, night time so switched on the lights and noticed the ambient lights flickering on the door panels.
Ran a fault check and this fault came back. Footwell lights etc all working fine but ambients flickering then stopped completely.
Cleared the fault codes, switched back on, flickering again then off, repeated processs several times, but same thing keeps happening and fault just keeps coming back.
Any ideas anyone, or has anyone experienced this before?
Thanks

Ace Rimmer · 11-13-2020, 12:47 PM

Spoke with my local BMW Tech guy and he said this will more than likely be one of three problems:

1. A loose ground connection.
2. Failed ambient lighting strip.
3. Too much draw from the FEM module caused by aftermarket LED's etc connected to the same positive negative line of the ambient door lighting.

As the ambient lighting was flickering on and off for a few seconds before going off completely and then coming up with the fault, this meant that they were ok and must be a ground issue. After removing a door panel I found the ground wire was loose to the connector, after putting it back insecurely then clearing the fault, all was back up and running!

minulache · 12-06-2023, 12:35 PM

Which door panel was it?

11-11-2020, 01:52 PM	#1
Ace Rimmer Private 24 Rep 75 Posts Drives: BMW F32 Join Date: Dec 2019 Location: UK iTrader: (0)	CAS FAULT CODE 8042C6 Ambient light 1 has short circuit I have this issue happening today, CAS fault code 8042C6. Got into the car, night time so switched on the lights and noticed the ambient lights flickering on the door panels. Ran a fault check and this fault came back. Footwell lights etc all working fine but ambients flickering then stopped completely. Cleared the fault codes, switched back on, flickering again then off, repeated processs several times, but same thing keeps happening and fault just keeps coming back. Any ideas anyone, or has anyone experienced this before? Thanks
	Appreciate 0 Tweet Quote

11-13-2020, 12:47 PM	#2
Ace Rimmer Private 24 Rep 75 Posts Drives: BMW F32 Join Date: Dec 2019 Location: UK iTrader: (0)	All sorted Spoke with my local BMW Tech guy and he said this will more than likely be one of three problems: 1. A loose ground connection. 2. Failed ambient lighting strip. 3. Too much draw from the FEM module caused by aftermarket LED's etc connected to the same positive negative line of the ambient door lighting. As the ambient lighting was flickering on and off for a few seconds before going off completely and then coming up with the fault, this meant that they were ok and must be a ground issue. After removing a door panel I found the ground wire was loose to the connector, after putting it back insecurely then clearing the fault, all was back up and running!
	Appreciate 0 Quote

12-06-2023, 12:35 PM	#3
minulache Private First Class 52 Rep 119 Posts Drives: BMW 4 F36 & E92 N55 LCI Join Date: Jun 2023 Location: Bucharest iTrader: (0)	Which door panel was it?
	Appreciate 0 Quote