XC70: Electrical Headlamp failure service required

[rob s80]

Message on the 2008 V70 SE Lux

To start, the message wasn't always on, but I got vida and dince up and running again now that I have a Volvo again and sure enough I was playing around with it, checking features, codes and settings.

I went into HCM and did the calibration and the headlights go up and down fine and all shows well, I can move them up down and adjust etc, all good.

After doing it all that's when the warning message comes up, so I went and checked the DTC code and it was HCM - B104154.

https://www.dtcdecode.com/Volvo/HCM-B104154

And when I go in and check calibration it's saying rear axle is calibrated but the front axle is not calibrated in relation to the headlights.

So where do I go from here ? I bet this is something I can't fix myself !

[dingov70]

Hello there , I suggest unclipping the link arm for the front sensor . aim front of car agasint a wall , run engine & turn on headlights , then move arm up & down . Pausing at either end of the movement to see if light alter their aim point , they should move .

IF they do not , the most probable reason is a duff sensor , see many makes with these issues at MOT time

[rob s80]

Originally Posted by dingov70

Hello there , I suggest unclipping the link arm for the front sensor . aim front of car agasint a wall , run engine & turn on headlights , then move arm up & down . Pausing at either end of the movement to see if light alter their aim point , they should move .

IF they do not , the most probable reason is a duff sensor , see many makes with these issues at MOT time

Hey thanks for that reply.

I "think" the headlight setup is the active bi-xenon - auto leveling one, as in I don't have an adjustment inside on the dash for them.

Everytime I start the car, it's usually pointing at the house and I can see them both go down and up each time, suggesting both motors are working up and down.

Would this be what you refer to or will I do as you suggest anyway ? And if so how would I go about doing that ?

Thank you !

[dingov70]

Yup they are the ones , the up & down is system check . After that the sensors monitor the attitude of the car front to rear and alter lights to maintain level beam pattern .

You will find the sensors fixed to a suspension arm or close to it , usully on one side only

[ferg55]

You could try changing the battery, it worked for me when this message appeared (I had poor start problems too).

[rob s80]

Originally Posted by dingov70

Yup they are the ones , the up & down is system check . After that the sensors monitor the attitude of the car front to rear and alter lights to maintain level beam pattern .

You will find the sensors fixed to a suspension arm or close to it , usully on one side only

Oh right , ok so, is there a correct procedure for calibrating the sensor then or how does one do that ?

@ferg55

Thanks ferg, but had a new battery put in recently, when I got the car it had a battery in it that was smaller than OE so I got the correct one in. Never an issue with starting or low power etc. Thankfully !

[dingov70]

NO idea about calibrating , but would think that any decent diagnostic scanner would have the abililty to perform calibration . Vide & Dice definately Snap-on pretty sure they can as well . they may well be fit & forget & self calibrate

[Model flyer]

The front sensor is fitted to the front off side wishbone with a plastic link arm connected with a small ball joint at each end. Easy to check and change. Not sure weather a new one would need calibrating.
My V70 started showing the same warning every time I started it but was caused by a failing battery,worth checking first.

[TerryU]

Originally Posted by Model flyer

The front sensor is fitted to the front off side wishbone with a plastic link arm connected with a small ball joint at each end. Easy to check and change. Not sure weather a new one would need calibrating.
My V70 started showing the same warning every time I started it but was caused by a failing battery,worth checking first.

Would you have any pics of the sensor to clearly identify it ?

I have this issue with a “ new to me “ xc70 and I’m trying to resolve faults/ issues...
Cheers...

By the way ... I love this car already and I’m pi55ed that I didn’t have one before now!
Terry

[37 RUBY]

Originally Posted by TerryU

Would you have any pics of the sensor to clearly identify it ?

It looks similar to this. Turn wheels full lock to the right then look under r/h wheel arch in front of drive train. You will note that it was made by Ford as it bears the dreaded FoMoCo logo.

Originally Posted by TerryU

I have this issue with a “ new to me “ xc70 and I’m trying to resolve faults/ issues...
Cheers...

Have you access to Vida? If so, just bear in mind that any DTC you have is because of failed communication from the sensor via the HCM which communicates this to the CEM.

Ironically a friend has a similar issue and I was looking through Vida yesterday. There is a work through to test Voltage and grounds at the line of the connector. I don't have it to hand for the pin numbers as I've loaned my Vida to him but it refers to 5 volt supply on I think pins 1 & 4 (check this !!!)and gives the pin numbers to check the grounds. It also describes that the resistance at the sensor pins should give a linear ohm reading when moved through its full range.

Be open minded to an issue at the HCM underneath the headlamp. Another forum user identified a HCM issue but I can't find that post. I do know that they identified that a replacement HCM substitute from a BMW that is cheaper than the Volvo unit but identical in operation. See here...https://www.ebay.co.uk/itm/Headlight...y/362699110483

That said, the sensor under the arch is subject to water and road grime and over enthusiastic jet washer hero's - remove the connector and check for corrosion.

If you do identify the sensor to be at fault I can only suggest getting the numbers from it, which will be Ford part numbers, and then ring Volvo and Ford as a comparison for price.

Originally Posted by TerryU

By the way ... I love this car already and I’m pi55ed that I didn’t have one before now!
Terry

...and so you should be