Sudden emergency braking fault

[jaapv]

It happened to me too (it has been described on the forum once before) Driving on the motorway with no traffic in front of me, 120 Kph, on ACC. Suddenly the "brake" warning started flashing and the car started a full emergency stop, after maybe 1 sec it released the brakes again. Fortunately there was no traffic close behind either. This was the first and only time it did that in 35.000 Km.
As it happened I was on my way to my dealer. They contacted Mitsubishi who connected to the car to do a readout of the FCM module.
Then they reinstalled the FCM software and the dealer recalibrated the system. The dealer told me they found several corrupted pieces of software.
Driving home the system functioned differently than ever before, more sensitive and now there is a real difference between the close and far settings.
Mitsubishi will analyze the collected data further and I may be asked to let them have the car for a full day for a complete readout. (I hope not...)

FWIIW...

 

[Regulo]

Which raises the question - if this had resulted in a "rear-ender", who would be at fault? I suppose we're all expected to be able to stop in good time if the car in front brakes, but an emergency stop for no reason? Glad I've got a 4H.

 

[jaapv]

In all cases Mitsubishi - I am insured with them... :mrgreen:

 

[Trex]

It happened to me too (it has been described on the forum once before) Driving on the motorway with no traffic in front of me, 120 Kph, on ACC. Suddenly the "brake" warning started flashing and the car started a full emergency stop, after maybe 1 sec it released the brakes again. Fortunately there was no traffic close behind either. This was the first and only time it did that in 35.000 Km.
As it happened I was on my way to my dealer. They contacted Mitsubishi who connected to the car to do a readout of the FCM module.
Then they reinstalled the FCM software and the dealer recalibrated the system. The dealer told me they found several corrupted pieces of software.
Driving home the system functioned differently than ever before, more sensitive and now there is a real difference between the close and far settings.
Mitsubishi will analyze the collected data further and I may be asked to let them have the car for a full day for a complete readout. (I hope not...)

FWIIW...

Hi jaapv,

That sounds scary. Did this give you a "fright". It almost sounds like the radar at the front of the Phev has "seen" something that was not there and then goes into Forward Collision Mitigation. I also have Adaptive Cruise Control with Forward Collision Mitigation and this does indeed sound worrying. I might just start using normal cruise control mode (but that might not help ) until more information is found about this problem.

A recall could be coming.

Can I just ask whether you use a OBD-II reader like Torque or DashCommand?

Regards Trex.

 

[jaapv]

No, it surprised me, I don't frighten that easily.
It had nothing to do with ACC. It was an FCM module fault.
I don't have an OBD reader, and it would not have helped. It cannot read out the full module software like Mitsubishi can.

 

[Trex]

It had nothing to do with ACC. It was an FCM module fault.
I don't have an OBD reader, and it would not have helped. It cannot read out the full module software like Mitsubishi can.

Hi jaapv,

That's why I wrote : " (but that might not help )" when I wrote : " I might just start using normal cruise control mode".

But if you look at the Canbus schematic in the sticky the ACC/FCM module (on the MAIN CAN-C network) are the same module.

The only reason I brought up the OBD reader was as a cause of the problem when you wrote : "The dealer told me they found several corrupted pieces of software. " ie the OBD reader (they can also write in some cases) caused the corruption. We can rule that out because you do not use one.

Regards Trex.

 

[jaapv]

As I understand it ACC and FCM are separate, but related modules that use the same radar transmitter/receiver.
Ah - yes -now I understand your OBD query.
Actually I think that the problem existed from new. I had been complaining to my dealer several times before that the FCM was unreliable in that the function was variable, but they could not find anything wrong with it, reason they went directly online with Mitsubishi now. The ACC has always been functioning perfectly and still does.

 

[Trex]

As I understand it ACC and FCM are separate, but related modules that use the same radar transmitter/receiver.
Ah - yes -now I understand your OBD query.

Hi Jaapv,



I put a red oval around the module in the schematic.

Can I also ask if you have had any problems with the update service done through the Wi-Fi on the mobile phone app?

Regards Trex.

 

[Trex]

As I understand it ACC and FCM are separate, but related modules that use the same radar transmitter/receiver.
Ah - yes -now I understand your OBD query.
Actually I think that the problem existed from new. I had been complaining to my dealer several times before that the FCM was unreliable in that the function was variable, but they could not find anything wrong with it, reason they went directly online with Mitsubishi now. The ACC has always been functioning perfectly and still does.

Hi jaapv,

Oops, you were editing your post when I wrote out mine.

You mean that the car interval settings never worked properly from new when you wrote in the first post : "Driving home the system functioned differently than ever before, more sensitive and now there is a real difference between the close and far settings."

The car intervals settings is part of the Adaptive Cruise Control I think (anybody else? My wife is away with the Phev with the owner's manual) not the Forward Collision Mitigation . Separate functions in the same module. But both ACC and FCM use the Radar at the front of Phev.

If you have been having car interval problems from new (ACC) and now a sudden emergency braking fault (FCM) different functions same module, same radar it indeed might be just your Phev and anyone else with those options might be ok including myself. Your part of ACC/FCM module that "talks" to the radar may have been faulty or corrupted.

I might go check the car interval settings on my Phev, have not adjusted those settings lately, and make sure they are working correctly just to put my own mind at ease.

Or pull the fuse on the ACC and FCM and normal cruise control might still work (probably not). My wife and sons both drive my Phev and if this problem (Sudden emergency braking fault) happened with a big semi-trailer truck behind them. They love using ACC which we also had on the Prius.

Regards Trex.

 

[jaapv]

No, not interval problems with the ACC, problems with the “ far” and “near” settings of the FCM.. Set to “far” the FCM would mostly still react (or rather not react) as if it were set to “near” and sometimes properly.
The distance intervals on ACC have always behaved properly. I posted about the FCM, not the ACC.
I did not do that update (or maybe I did, I am not sure), my iPhones work well from the beginningl.

 

[Trex]

No, not interval problems with the ACC, problems with the “ far” and “near” settings of the FCM.. Set to “far” the FCM would mostly still react (or rather not react) as if it were set to “near” and sometimes properly.
The distance intervals on ACC have always behaved properly. I posted about the FCM, not the ACC.
I did not do that update (or maybe I did, I am not sure), my iPhones work well from the beginningl.

Ok, sorry jaapv my mistake. We have never adjusted that setting.

I hope they find what caused this problem.

Regards Trex.

 

[jaapv]

Well, it seems to be fine now and Mitsubishi is treating this as a "dangerous fault" and analyzing the readout further, so fingers crossed.

 

[Trex]

Well, it seems to be fine now and Mitsubishi is treating this as a "dangerous fault" and analyzing the readout further, so fingers crossed.

Well I could not find the fuse to disconnect ACC/FCM module. Looks like it is something that Mitsubishi do not want the owner to turn off ie not in owner's manual.

Regards Trex.

 

[jaapv]

Why not use the switch on the dash to turn it off?

 

[anko]

Just two weeks ago, Dutch newspaper AD featured an article about Top 5 Car brands in terms of number of recalls. Mitsubishi held third place. Most 'interesting' recall (in terms of this topic), was about a fault in the Outlander (what they called) Cruise Control, which could lead to the wall of a tunnel being recognized as a pedestrian. As a result, the car would brake.

The article didn't mention specific models or even model years.

http://www.ad.nl/ad/nl/1006/Auto/article/detail/3874726/2015/02/27/Top-tien-autofabrikanten-met-de-meeste-terugroepacties.dhtml

 

[jaapv]

Sounds similar, but this was on an open motorway without any traffic near.

 

[Trex]

Why not use the switch on the dash to turn it off?

From what I read, in owner's manual, switch only turns off warnings not actual action of applying brakes in emergency.

Regards Trex.