C70 hood wont close Hall Sensor 3 Faulty

[DLM48]

Lovely hot sunny weather so went for a long drive with the hood and windows down

Stupidly got sunburnt

BUT the Dreaded C70 hood issue has arrived

at my intended destination, Inveraray wanted to get out for a P&T stop

So hood up.......................


NOOOOOOOOOOOOOOOOOOOOOOOOOO NUFFIN

went to open the boot

NOOOOOOOOOOOOOOOOOOOO NUFFIN DOING THERE AS WELL

Thinks WTF, so after pondering a bit I put the windows up

and try the hood open switch, success the windows drop and the then close again

dash says hood open

out to the boot and the boot now opens

try the yellow switch NUFFIN

Back into the car and now have a Hood error message GRRRRRRRRRRRRRRRRR

more pondering so do the windows and the hood open switch and get the same hood open message

back to the boot and it opens again

give everything a good look and a shake everything looks fine

back to try to close the hood again I need to have it closed if I am to leave the car as I have a few thousand pound of DSLR Cameras in the back seats that need to go into the boot and they cannot go in with the roof in the stored position

NOPE DEAD as a Do Do but now get a hood unlocked message

try to move the car, alarm goes crazy with a Don't Drive the Car you idiot message

so back to the windows and the hod open switch and get the hood open message again

boot opens and no messages on the dash so it is a quick U turn and back home.

Get my tablet out and fire up VIDA connect the DICE and get lots of error messages

do a reset and clear them and test the hood

HALL SENSOR 3 is faulty. (HS3)

SO how do I get to that

I think I need to remove the back seats and the side and rear trim

so anyone got the correct and detailed info on

ONE removing all that I need to remove to get access to HS3
TWO Where is HS3
THREE Probably a broken wire on HS3 is that a logical deduction
FOUR how do I replace HS3 and is this a Volvo Part

thanks in anticipation

[FredGraham]

Hiya,
Don't know if this will help you get to the root of your problem.
Cheers
Fred
https://www.volvoclub.org.uk/tech/c7...ullDetails.pdf

[JohnM 855 T5R]

About 5 years ago I had a hood unlocked message (even though it was obviously locked) which meant I had to drive 60 miles with the beeping alarm deafening me all the way. As it was under my Volvo Selekt warranty, took it to the dealer. That showed a sensor fault generating an out of position code but the sensor tested OK!
The service manager had a brainwave - pulled back the boot trim to get to the roof computer, pulled the connector and arrrrragh - all green corrosion from presumably moisture ingress. Throughly cleaned the connectors and bingo - all worked fine again. He taped the connector joint to make sure all stayed dry. As I said, that was 5 years ago and no trouble since.

So, you might want to take a look there. He told me that connector issues are not uncommon and can lead to all sorts of sensor errors.

Regards
John

[Spacemonkey]

Originally Posted by FredGraham

Hiya,
Don't know if this will help you get to the root of your problem.
Cheers
Fred
https://www.volvoclub.org.uk/tech/c7...ullDetails.pdf

Wow, that's awesome! I too have a dead H3 sensor, but mine only stops the closed roof from lifting for boot access. I still have to find out how to replace this too, as well as pretty much all my speakers so this is going to be fun...

[Clan]

it wont be the sensor itself it will be the wiring broken where it bends near the left side of the boot behind the back seat , there is a bunch of black wires ,, It needs simple wiring fault tracing .. a repair need to be special for it not to happen again . you can buy fine multi strand wire soft rubber coated for such a purpose . .

[Spacemonkey]

Have you got an example of the type of wiring? I'd rather have the wire to hand so that I only have to remove everything once...


And today after reading the pdf I realised what sensor 3 did. And I had a thought- what if I simply hadn't opened the boot far enough to engage S3? so I pushed the boot a bit higher and it went. The pressed the yellow button and it burst into life and raised the roof...slightly. Bugger... Roof service warning.. And couldn;t shut the boot or move the roof. Double bugger... Eventually worked out the 'press yellow button for 5 seconds' bit which lowered the roof back into the boot properly. Andf shut the boot. Excellent! But drive off and it starts chiming and shouting out about the roof not being locked. Triple bugger. I open the boot and hold the yellow button and it continues whirring but nothign happens. I'm terrified now that something is breaking, or soon will. This is a modern Volvo after all, not a bombproof 240... Eventually I relent and keep the button held abnd after about 10 seconds of whirring two latches flip down and the whirring stops... and the display is all good. So I fully raise and lower the roof . All good. Drive off- all good... Minor heart attack over. Hope this is useful to someone when they google this in years to come.

[Baxlin]

On mine, when pressing the ‘yellow button’ disabled the roof in the down position, in panic I just kept repeatedly pressing and holding down the roof close button, and eventually the roof worked.

It continued to work OK while I had the car, but obviously I didn’t try to use the yellow button again. I sold the car in this state having explained the problem to the Volvo-savvy buyer.

[Clan]

Originally Posted by Spacemonkey

Have you got an example of the type of wiring? I'd rather have the wire to hand so that I only have to remove everything once...


And today after reading the pdf I realised what sensor 3 did. And I had a thought- what if I simply hadn't opened the boot far enough to engage S3? so I pushed the boot a bit higher and it went. The pressed the yellow button and it burst into life and raised the roof...slightly. Bugger... Roof service warning.. And couldn;t shut the boot or move the roof. Double bugger... Eventually worked out the 'press yellow button for 5 seconds' bit which lowered the roof back into the boot properly. Andf shut the boot. Excellent! But drive off and it starts chiming and shouting out about the roof not being locked. Triple bugger. I open the boot and hold the yellow button and it continues whirring but nothign happens. I'm terrified now that something is breaking, or soon will. This is a modern Volvo after all, not a bombproof 240... Eventually I relent and keep the button held abnd after about 10 seconds of whirring two latches flip down and the whirring stops... and the display is all good. So I fully raise and lower the roof . All good. Drive off- all good... Minor heart attack over. Hope this is useful to someone when they google this in years to come.

, the sensor uses hardly any current at all . RS Components would have the wire by the metre .

[Spacemonkey]

Looks like I'll be rewiring my headlamp first. had a bulb failure warning the other day. The big connector was furred up green so cleaned that up, bulb was fine. Worked fine for a couple of days then a brief failure warning, but all worked when I finished work so left it. Failed again yesterday so had a look. The wires to the bulb connector were cracked and split, bulb connector and bulb base melted. Bugger again....Standard bulb in there btw.

[Simmy]

some times the roof can get confused if some thing is done wrong .try locking the car and leave for a few mins then retry making shure the load cover is clicked in to the catches and dont forget to press the brake pedal and dont stop half way through the roof closeing only do full operations up or down wait for dash message for notification of completion