R4 PHEV... Strange display darkening problem

[Nick72]

This is a new one. Very long road trip this weekend. Coming back on the motorway and both the MID and infotainment display went very dark. Could barely see anything on them. Tried as I might to faff finding the controls I couldn't get either brightness up. Midday, bright daylight. Were fine one minute then very very dim for 30 min to an hour. 

Eventually pulled off the motorway to investigate. Switched the permanent day mode on for the infotainment settings which fixed it there. Couldn't do anything for the MID. Pressed the little mode selection button next to the dials and it was already set of full brightness. Clearly it wasn't.

Had to carry on driving and use the HUD for speed check, which I do mostly so no big deal.

Strangely it all went bright again about an hour later (the MID). Then half hour after that it went dim again for the hour. Ambient external light barely changing during all of this time. It was bright and sunny and I wasn't going under tunnels or bridges when it was dim. It was dim for way too long.

Anyone know where the ambient light sensor is which modes the two displays in terms of night and day mode? Seemed it was self switching both displays into night mode randomly and staying like that for long periods of time. Like, an hour kind of time.

I'm thinking the ambient light sensor is either dirty or faulty. I think faulty only because this was repeated a couple of times. Dirt build up doesn't work like that unless I'm missing something, which I could well be.

 

Any thoughts anyone?

N

 

[ernieb]

I'd have thought if it was dirty etc., it would have been permanently bright? Sounds faulty or a poor connection.

I thought there was a light sensor on the dash but see image?

[spicyhotone]

Had the automatic headlights come on? Does that dim the MID? Certainly does dim the infotainment. If that was it, turning the headlights off (ie. off the auto setting) should fix it, and possibly back to the auto setting (ie. off & on again!) might fix it.

[Nick72]

On 10/17/2022 at 8:26 AM, spicyhotone said:

Had the automatic headlights come on? Does that dim the MID? Certainly does dim the infotainment. If that was it, turning the headlights off (ie. off the auto setting) should fix it, and possibly back to the auto setting (ie. off & on again!) might fix it.

I'll try that. Blooming thing is however working fine now.

[Nick72]

On 10/17/2022 at 7:27 AM, ernieb said:

I'd have thought if it was dirty etc., it would have been permanently bright? Sounds faulty or a poor connection.

I thought there was a light sensor on the dash but see image?

Wouldn't have thought back of the rear view mirror and bottom. Will check level of dirt on the windscreen where that sensor is pointing. All working fine now though. So strange.