New XC40 sudden power loss - safety issue

Faults and Technical chat for the Volvo XC40
berryberry
Posts: 25
Joined: Mon Dec 30, 2024 7:04 pm

Post by berryberry »

5 weeks after purchasing our new XC40 B3 Plus we took our first longer trip of 200 miles on 17 December . Whilst returning late evening in darkness around 2200hrs we approached a 60mph crossroads, slowed down by braking to a stop at the junction. The start/ stop function engaged and we checked left and right for traffic. There was a car heading in our direction from the right approx 1/2 mile away. We decided it was clear to cross, accelerated and after 10ft, the car came to a sudden stop with complete loss of power! We were like sitting ducks in the middle of the road, and with the oncoming car approaching, we quickly pressed the hazard lights. We had seconds to get out the car, but tried the start button before doing so, and mercifully the car started and we slowly drove off. Although traumatised we feel we have been lucky, as had the car not started or we been crossing the road at peak time the outcome may have been quite different!

We reported the incident to our Volvo dealership and they agreed to take the car in and look for fault. They reported back next day that they could find no error with the car either mechanical or in the software. We asked them to specifically review the time frame of the previous evening from 2155-2205. They advised that they were unable to do so, but that Volvo Technical UK could dig deeper. We have been advised that Volvo Technical also found no fault codes, but to date no one from Volvo has been able to show us that they have checked the specific actions during that time frame, as we are sure that the detailed history will show that the car made an involuntary stop. We believe that they have simply conducted fairly basic diagnostic checks but not forensically examined specific commands such as accelerator depressed at 21.59.30 etc.

It might also be useful to know that the original car delivery was delayed 10 weeks due to unexplained software/coding issues.

Could these two issues be linked?
Has this happened to anyone else?
Can Volvo UK look into the historical data of a car during a specific time frame, detailing all specific commands second-by-second?

We are absolutely certain what happened that night and we are extremely fearful of a repeat - a chance we are simply not willing to take.

AldridgeAndy
Posts: 103
Joined: Sun Nov 12, 2023 1:08 am

Post by AldridgeAndy »

Any chance you have a dash cam and footage of the incident to share with your dealership and Volvo UK?
2024 MY - Volvo XC40 B3 Plus Dark
berryberry
Posts: 25
Joined: Mon Dec 30, 2024 7:04 pm

Post by berryberry »

Afraid not Andy, we don't have dash cam.

There were two of us in the car, and we both witnessed the episode. We previously had an XC60 with no issues. From our investigations it would appear that Volvo UK Technical can do a forensic search of the history of the time frame. We have asked if they can check the sequence of events from 2155-2205, to see if our actions matched the car performance. i.e. brake, stop and start commence, accelerator depressed, car involuntary stopped, hazard lights switched on, starter switch pressed. Our question to Volvo is why we would have had to start the car again when we had never stopped it. We have seen some previous posts on this forum where people have experienced a similar unexplained event. Could it be a software coding issue that is affecting some XC40 models?
GKSmith
Posts: 86
Joined: Sat Feb 10, 2024 10:50 am

Post by GKSmith »

berryberry wrote: Mon Dec 30, 2024 7:51 pm 5 weeks after purchasing our new XC40 B3 Plus we took our first longer trip of 200 miles on 17 December . Whilst returning late evening in darkness around 2200hrs we approached a 60mph crossroads, slowed down by braking to a stop at the junction. The start/ stop function engaged and we checked left and right for traffic. There was a car heading in our direction from the right approx 1/2 mile away. We decided it was clear to cross, accelerated and after 10ft, the car came to a sudden stop with complete loss of power! We were like sitting ducks in the middle of the road, and with the oncoming car approaching, we quickly pressed the hazard lights. We had seconds to get out the car, but tried the start button before doing so, and mercifully the car started and we slowly drove off. Although traumatised we feel we have been lucky, as had the car not started or we been crossing the road at peak time the outcome may have been quite different!

We reported the incident to our Volvo dealership and they agreed to take the car in and look for fault. They reported back next day that they could find no error with the car either mechanical or in the software. We asked them to specifically review the time frame of the previous evening from 2155-2205. They advised that they were unable to do so, but that Volvo Technical UK could dig deeper. We have been advised that Volvo Technical also found no fault codes, but to date no one from Volvo has been able to show us that they have checked the specific actions during that time frame, as we are sure that the detailed history will show that the car made an involuntary stop. We believe that they have simply conducted fairly basic diagnostic checks but not forensically examined specific commands such as accelerator depressed at 21.59.30 etc.

It might also be useful to know that the original car delivery was delayed 10 weeks due to unexplained software/coding issues.

Could these two issues be linked?
Has this happened to anyone else?
Can Volvo UK look into the historical data of a car during a specific time frame, detailing all specific commands second-by-second?

We are absolutely certain what happened that night and we are extremely fearful of a repeat - a chance we are simply not willing to take.
What AAOS version are you on? 3.3.16? Do you have the Intelligent Speed Assist on, with Adaptive Pedal Response on?
Thanks
Gavin
Volvo MY25 XC40 B3 Plus Onyx Black
berryberry
Posts: 25
Joined: Mon Dec 30, 2024 7:04 pm

Post by berryberry »

Hi Gavin

I'm afraid we have no idea. The Volvo is currently with the Volvo dealership as we have refused to take it back until they investigate the incident further. We got the car on 20 November and had driven approx 700 miles prior to the incident. Would any of the above cause an involuntary stop? We drove to the 60mph junction, pressed the brake to stop the car at the junction, the stop start appeared to engage, when clear to drive forward we drove off approx 10ft and then the car just died, all power gone completely, no stall, no mechanical slow down just complete loss of power. Put on the hazards, pressed the stop start in an effort to get moving before being hit by the oncoming car and the engine re started. We have asked Volvo to check the sequence of events, as we believe that Volvo technical can access this info. So far they say no error codes or mechanical found, but there may be no error code if the car has been wrongly programmed to start with, we are sure it is a software issue.
berryberry
Posts: 25
Joined: Mon Dec 30, 2024 7:04 pm

Post by berryberry »

Hi Gavin

We have checked the Volvo App the software is 3.3.16 if that helps
GKSmith
Posts: 86
Joined: Sat Feb 10, 2024 10:50 am

Post by GKSmith »

I was just curious regarding the software version. Have you had any news?
Thanks
Gavin
Volvo MY25 XC40 B3 Plus Onyx Black
neilgorin
Posts: 24
Joined: Mon Dec 11, 2023 2:15 am

Post by neilgorin »

Your engine will go off long before the junction if you're slowing, the B3/B4 will power down the engine the moment you lift off the throttle at any speed above 28mph if the conditions are right.

The odd thing is that you had to use Start to restart the engine as that suggests a loose connection has told the car that you've turned the thing off, as the normal situation is that the moment you touch the throttle at any speed the engine will restart - you can see this on the rev counter, dial drops to zero and a green symbol appears whenever the engine is off.
berryberry
Posts: 25
Joined: Mon Dec 30, 2024 7:04 pm

Post by berryberry »

No news Gavin, still awaiting an outcome, the car is still with Volvo but they have 3 more working days to respond.

Hi Neil
The situation that night was that we broke and slowed down to stop at the junction, and the stop/start engaged. We then when it was safe to do so, accelerated, and all was well and the car moved forward 10ft, it then died! Complete loss of all power, lights, the lot. With hazard lights deployed and with seconds to get out of the car, we pressed the starter,the car started and we drove off. The key here is that the stop / start appeared to be working fine as we broke at the junction and then accelerated, it was the involuntary stop that gave us serious safety concerns.
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Moss
Posts: 265
Joined: Wed Apr 29, 2020 8:52 pm
Location: Belgium & France

Post by Moss »

berryberry wrote: Mon Dec 30, 2024 7:51 pm 5 weeks after purchasing our new XC40 B3 Plus we took our first longer trip of 200 miles on 17 December . Whilst returning late evening in darkness around 2200hrs we approached a 60mph crossroads, slowed down by braking to a stop at the junction. The start/ stop function engaged and we checked left and right for traffic. There was a car heading in our direction from the right approx 1/2 mile away. We decided it was clear to cross, accelerated and after 10ft, the car came to a sudden stop with complete loss of power! We were like sitting ducks in the middle of the road, and with the oncoming car approaching, we quickly pressed the hazard lights. We had seconds to get out the car, but tried the start button before doing so, and mercifully the car started and we slowly drove off. Although traumatised we feel we have been lucky, as had the car not started or we been crossing the road at peak time the outcome may have been quite different!

We reported the incident to our Volvo dealership and they agreed to take the car in and look for fault. They reported back next day that they could find no error with the car either mechanical or in the software. We asked them to specifically review the time frame of the previous evening from 2155-2205. They advised that they were unable to do so, but that Volvo Technical UK could dig deeper. We have been advised that Volvo Technical also found no fault codes, but to date no one from Volvo has been able to show us that they have checked the specific actions during that time frame, as we are sure that the detailed history will show that the car made an involuntary stop. We believe that they have simply conducted fairly basic diagnostic checks but not forensically examined specific commands such as accelerator depressed at 21.59.30 etc.

It might also be useful to know that the original car delivery was delayed 10 weeks due to unexplained software/coding issues.

Could these two issues be linked?
Has this happened to anyone else?
Can Volvo UK look into the historical data of a car during a specific time frame, detailing all specific commands second-by-second?

We are absolutely certain what happened that night and we are extremely fearful of a repeat - a chance we are simply not willing to take.
I don’t think this forum is the right place to seek a solution to your problem. Your Volvo Cars dealer is the right place, or Volvo UK if your dealer can’t solve the problem.

Anyhow, this is my sincere advice to you : if you don’t trust a car – this car or any other car – rightfully or wrongfully so and whoever is right or wrong, do not use it. There are many solutions to your problem : sell the car and buy something else, or ask the Volvo dealer to sell the thing for you, and get you something different.
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