POSSIBLE BIMODAL/BATTERY PROBLEMS

[Josh.]

ALSO POSTED IN TECHNICAL DISCUSSIONS, BUT AS THIS MIGHT BE RELATED TO THE AUSTRALIAN BIMODAL I THOUGHT I MIGHT PUT IT HERE AS WELL
Apologies if this is in the wrong area.

We picked up a GT in Australia on Saturday with the local bimodal exhaust fitted by the dealership.

On Thursday morning the car wouldn't start, battery was 8.4V. I Needed to put a power supply on the alternator fuse box in the engine bay in order to open the boot in order to get at the battery to test and jump start(I couldn't access the boot through the back seats as our two child car seats were in and tethered into the boot.
Dealer picked up the car, i advised them to check the exhaust, that afternoon they had charged the battery all day, told me the exhaust wasn't the problem, but that something was pulling 4A while car was shut down. They later dropped it back and said the exhaust was the problem, they had disconnected the harness and would get a new ecm/harness and replace.

Friday morning the car wouldn't start, battery at 6V, same process, dealer takes car into town, leaves in carpark all day, starts in afternoon and drives into workshop.
Dealer quizzes me because the car didn't lose charge throughout the day, yes we are turning it off properly, yes lights are off, yes we are locking it, no we aren't leaving it on accessories(which shouldn't run the battery flat overnight anyway).
My only out there thoughts were that because we were nosing it right up to the garage wall the radar or front sensors were doing something to drain the battery, or
Something is coming on when the day/night sensor is in the dark, which might explain why the battery didn't lose charge today.

Any help appreciated as at this stage it seems like I am going to have to find the problem myself.

 

[ShannonC]

Unlikely it would be the exhaust unless dealer tapped into a wrong fuse and it's drawing constant power. Also unlikely to be radar as when car shuts down it should go passive like all other systems. First I've heard of a fault like this.
Perhaps pull the exhaust power and leave it overnight so that least you can eliminate one possibility.

 

[Josh.]

Unlikely it would be the exhaust unless dealer tapped into a wrong fuse and it's drawing constant power. Also unlikely to be radar as when car shuts down it should go passive like all other systems. First I've heard of a fault like this.
Perhaps pull the exhaust power and leave it overnight so that least you can eliminate one possibility.

They first diagnosed it as the exhaust and yes last night it was disconnected so that has been ruled out, Also yes the radar should go passive, but the dealer told me they have had instances of the sensor that automatically opens the boot being faulty and staying active and draining the battery so any component can fail and do things it isn't supposed to do

 

[Bigbikes]

They first diagnosed it as the exhaust and yes last night it was disconnected so that has been ruled out, Also yes the radar should go passive, but the dealer told me they have had instances of the sensor that automatically opens the boot being faulty and staying active and draining the battery so any component can fail and do things it isn't supposed to do

l have bi-modal and no battery issues at all, also i park mine in my garage close to some boxs in front of it and it sits there all week till i drive it on weekends...open fuse cover and take pic of the position the tapped into ok i have posted a pic of mine before , you can compare ..cheers

 

[Josh.]

l have bi-modal and no battery issues at all, also i park mine in my garage close to some boxs in front of it and it sits there all week till i drive it on weekends...open fuse cover and take pic of the position the tapped into ok i have posted a pic of mine before , you can compare ..cheers

They still have the car so I can't check, however yesterday they said the fault was that the ecm was driving the solenoids open constantly instead of open then de-energise, but now that that's ruled out they seem to think I'm doing something wrong, funny they were so confident yesterday

 

[ShannonC]

Here's a pic of bi-modal fuse tap.

 

[Bigbikes]

Here's a pic of bi-modal fuse tap.
View attachment 31736

Thanks for that saved me finding mine again

 

[Josh.]

Here's a pic of bi-modal fuse tap.
View attachment 31736

Which fusebox is that?

 

[Cashie]

They first diagnosed it as the exhaust and yes last night it was disconnected so that has been ruled out, Also yes the radar should go passive, but the dealer told me they have had instances of the sensor that automatically opens the boot being faulty and staying active and draining the battery so any component can fail and do things it isn't supposed to do

Could the exhaust have been the cause of the original current drain and now the battery is failing?

 

[Josh.]

Could the exhaust have been the cause of the original current drain and now the battery is failing?

That was what i said to the dealer this afternoon, that their guys should had load tested the battery, the answer....

 

[ShannonC]

Which fusebox is that?

Driver side under dash/near door.

 

[Josh.]

Driver side under dash/near door.

What I can tell you is that mine is tapped into the fusebox on the drivers side of the boot, but all the fuseholders have power all the time so shouldn't matter...

 

[Cashie]

What I can tell you is that mine is tapped into the fusebox on the drivers side of the boot, but all the fuseholders have power all the time so shouldn't matter...

What do you mean they all have power all the time, isn't the BiModal meant to be connected to an accessories fuse?

 

[Josh.]

What do you mean they all have power all the time, isn't the BiModal meant to be connected to an accessories fuse?

Please elaborate, this might be something my dealer doesn't know about

 

[Cashie]

Please elaborate, this might be something my dealer doesn't know about

There are battery (powered all the time) fuses and accessory (only powered when the car is turned on) fuses.
I would have assumed the bimodal ECU and solenoids would have been powered off an accessory circuit/fuse so it isn't powered when the car is off.

 

[Josh.]

There are battery (powered all the time) fuses and accessory (only powered when the car is turned on) fuses.
I would have assumed the bimodal ECU and solenoids would have been powered off an accessory circuit/fuse so it isn't powered when the car is off.

Yeah I mainly meant elaborate on the bimodal being on accessories(maybe someone had been told this by the manufacturer or another dealer and maybe someone had been told why this is the case?)

 

[Cashie]

Yeah I mainly meant elaborate on the bimodal being on accessories(maybe someone had been told this by the manufacturer or another dealer and maybe someone had been told why this is the case?)

Not sure what you're asking, but i can not see why you wouldn't place the bimodal on an accessory circuit. You don't want any vampire current draw from the bimodal when the car is off.
Shannons above is tapped off one of the power outlet 20A fuses.

I'd say the rear fuses (or at least some of them) are accessory or ignition fuses too looking at what they power, the Amps, Heated Rear Window, Rear Seat Heaters etc..

 

[ShannonC]

Not sure what you're asking, but i can not see why you wouldn't place the bimodal on an accessory circuit. You don't want any vampire current draw from the bimodal when the car is off.
Shannons above is tapped off one of the power outlet 20A fuses.

I'd say the rear fuses (or at least some of them) are accessory or ignition fuses too looking at what they power, the Amps, Heated Rear Window, Rear Seat Heaters etc..

I think @Bigbikes has the same as mine, which I thought was a standard installation.

 

[Bigbikes]

I think @Bigbikes has the same as mine, which I thought was a standard installation.

Yes mines same as yours....plus they would be following the installation instructions.
I know when i first start mine you can hear the servos opening and closing.

 

[ShannonC]

Yes mines same as yours....plus they would be following the installation instructions.
I know when i first start mine you can hear the servos opening and closing.

Love the sound on cold start...resonates through my underground carpark.