Electronic Brake Booster Assembly - Help?

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Joined
Oct 12, 2018
Messages
5
Wife has owned a 2015 Leaf S for the last 2 years, been a fine little car, 27k on the odometer. A few nights back while parking, she experienced brake failure, to be exact - the brakes were still there but the power assist was gone.

Needless to say this troubled me so I scheduled a diagnostic at the local dealership. I googled the situation and found that when the 12v battery fails, similar situations can occur. I figured we'd hear that it was that, or maybe some sensor.

Got the call last evening, guy said it was the electronic brake booster assembly and that it wasn't covered under her power train warranty (certified pre owned). Total cost will be $2170. I am pretty shocked. Not even 30k miles and this?

Wondering if this even seems legit? Any advice or options I may not be thinking of?

Appreciate any and all info.

Thanks

Edit to update: Situation isn't sitting right with me so I went and picked up the car. Mysteriously the problem part changed, now it's not the electronic brake booster assembly, they were confused and it's actually the "intelligent brake actuator".

Seems fishy...

Please advise.
 
Surely the bumper to bumper is 3 years/36k at least?

Edit: Oh, I read your part about you only owning the car for 2 years. So I guess you bought used and it's out of warranty by a matter of months?

You might want to check what the "in service" date was, to make completely sure it's out of warranty. Used to be you could call 1-877-NO-GAS-EV and they would happily give you that info. You can also get it from a Carfax report or by calling a dealership service center.
 
Certified pre owned apparently it's only power train.

Whole thing seems off to me. I've owned many ICE conventional cars, 30k miles should be nothing. I'm just not believing the story.
 
Aintnobodyreally said:
Certified pre owned apparently it's only power train.

Whole thing seems off to me. I've owned many ICE conventional cars, 30k miles should be nothing. I'm just not believing the story.

CPO should still be the balance of all factory warranties. Powertrain on the LEAF was already 5 years/60k.
 
These may help, a bit:
http://www.mynissanleaf.com/viewtopic.php?t=21203
https://www.mynissanleaf.com/viewtopic.php?t=19555
http://www.mynissanleaf.com/viewtopic.php?t=24764

Unfortunately, Nicoclub had to remove their copies of the service manuals. They got a cease and desist from Nissan, which isn't surprising to me at all. Surprised they were up there for so long.
 
Hi, I really appreciate your response, great links, I'm going through them now.

I will say that my wife's leaf shows no warning lamps at all, and the dealership could not reproduce the issue.

Again I appreciate any and all thoughts.
 
mwalsh said:
Aintnobodyreally said:
Certified pre owned apparently it's only power train.

Whole thing seems off to me. I've owned many ICE conventional cars, 30k miles should be nothing. I'm just not believing the story.

CPO should still be the balance of all factory warranties. Powertrain on the LEAF was already 5 years/60k.

Checking into it, really appreciate it.
 
Update:

Nissan rep just told us they show our warranty is good until 2021, gave us a case number, taking copies of our documentation of the service visit and he is contacting the dealership. He chose his words carefully, but I got the distinct impression he didn't agree with how the dealership was going about things.

I hope this works out...
 
It sounds likely that a 12 volt battery failure is all that really occurred, and that the dealership just read the 'phantom codes' that were thrown when it failed. Put in a new, fully charged 12 volt battery (AGM if possible), reset all codes, and see if anything shows then.
 
LeftieBiker said:
It sounds likely that a 12 volt battery failure is all that really occurred, and that the dealership just read the 'phantom codes' that were thrown when it failed. Put in a new, fully charged 12 volt battery (AGM if possible), reset all codes, and see if anything shows then.
This doesn’t seem right to me where the car was already powered on and had been driving normally. Unless there was a failure of the DC-DC inverter why would a weak 12V battery suddenly cause this change (brakes operating normally and then not)? Many faults get attributed to the 12V, which is probably often true, but I’m not convinced that in all cases there isn’t some firmware crash involved.

What has been the conclusion? Now working fine and no fault found?
 
I have had brake and ABS issues caused by CAN bus communication problems with my 2015 (never with the 2011). It generally requires clearing trouble codes, disconnecting 12-volt battery, reconnecting 12-volt battery, and clearing trouble codes again to return everything to normal. It has probably happened about 5 pr 6 times in 67k miles. In my case, I have power assist, but it is really aggressive and kicks in suddenly when brake pedal is pressed nearly to the floor (there is little braking action until pedal is pressed that far and then it comes on suddenly). It usually happens when the car is started after being parked and is not necessarily related to a weak 12-volt battery, but a weak battery can be a contributing factor.
 
GerryAZ said:
I have had brake and ABS issues caused by CAN bus communication problems with my 2015 (never with the 2011). It generally requires clearing trouble codes, disconnecting 12-volt battery, reconnecting 12-volt battery, and clearing trouble codes again to return everything to normal. It has probably happened about 5 pr 6 times in 67k miles. In my case, I have power assist, but it is really aggressive and kicks in suddenly when brake pedal is pressed nearly to the floor (there is little braking action until pedal is pressed that far and then it comes on suddenly). It usually happens when the car is started after being parked and is not necessarily related to a weak 12-volt battery, but a weak battery can be a contributing factor.
Very interesting insights. If your car is a 2015 with these issues, is it not covered by Nissan under warranty and resolution could be sought? I would be very nervous about having my car with an expectation that the same issue would resurface multiple times.
 
dwl said:
GerryAZ said:
I have had brake and ABS issues caused by CAN bus communication problems with my 2015 (never with the 2011). It generally requires clearing trouble codes, disconnecting 12-volt battery, reconnecting 12-volt battery, and clearing trouble codes again to return everything to normal. It has probably happened about 5 pr 6 times in 67k miles. In my case, I have power assist, but it is really aggressive and kicks in suddenly when brake pedal is pressed nearly to the floor (there is little braking action until pedal is pressed that far and then it comes on suddenly). It usually happens when the car is started after being parked and is not necessarily related to a weak 12-volt battery, but a weak battery can be a contributing factor.
Very interesting insights. If your car is a 2015 with these issues, is it not covered by Nissan under warranty and resolution could be sought? I would be very nervous about having my car with an expectation that the same issue would resurface multiple times.

It appears to be a CAN bus communication issue and is so intermittent that it is hard to pinpoint a cause. Since I keep an original GID meter and a Bluetooth module for LEAF Spy plugged in to the OBDII port all the time, I cannot prove that the CAN bus communication problems would be there without the monitoring. Also, I sometimes have DCQC charger communication errors cause charging to be terminated. There are many computers (modules) on the CAN bus network so the root cause could be difficult to find. I don't want the dealer to blindly replace parts and perhaps cause other problems. If it ever becomes more than intermittent, I will take it in under the 6-year, 100,000-mile extended warranty (Nissan 3-year, 36,000-mile bumper-to-bumper and 5-year, 60,000-mile powertrain warranties are both expired).
 
GerryAZ said:
dwl said:
GerryAZ said:
I have had brake and ABS issues caused by CAN bus communication problems with my 2015 (never with the 2011). It generally requires clearing trouble codes, disconnecting 12-volt battery, reconnecting 12-volt battery, and clearing trouble codes again to return everything to normal. It has probably happened about 5 pr 6 times in 67k miles. In my case, I have power assist, but it is really aggressive and kicks in suddenly when brake pedal is pressed nearly to the floor (there is little braking action until pedal is pressed that far and then it comes on suddenly). It usually happens when the car is started after being parked and is not necessarily related to a weak 12-volt battery, but a weak battery can be a contributing factor.
Very interesting insights. If your car is a 2015 with these issues, is it not covered by Nissan under warranty and resolution could be sought? I would be very nervous about having my car with an expectation that the same issue would resurface multiple times.
It appears to be a CAN bus communication issue and is so intermittent that it is hard to pinpoint a cause. Since I keep an original GID meter and a Bluetooth module for LEAF Spy plugged in to the OBDII port all the time, I cannot prove that the CAN bus communication problems would be there without the monitoring. Also, I sometimes have DCQC charger communication errors cause charging to be terminated. There are many computers (modules) on the CAN bus network so the root cause could be difficult to find. I don't want the dealer to blindly replace parts and perhaps cause other problems. If it ever becomes more than intermittent, I will take it in under the 6-year, 100,000-mile extended warranty (Nissan 3-year, 36,000-mile bumper-to-bumper and 5-year, 60,000-mile powertrain warranties are both expired).
If the issue is intermittent, could you please confirm that when it occurs the result is on-going loss of normal brake action until codes are cleared and 12V disconnected. A temporary loss of comms is one thing but for it to extend to continuing failure until resets are done is another level. It is suggesting to me there may be some "freezing" of the communication channel or the firmware.
 
Once it happens, the only way to restore completely normal power-assisted braking action is to clear error codes and disconnect/reconnect 12-volt battery. It appears that the communications involving the brake and ABS modules is frozen until reset. As I said before, it has only happened a few times in 68,000 miles so it is not a common occurrence.
 
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