Parasitic battery drain. Possibly EFI

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Sonac
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Parasitic battery drain. Possibly EFI

Post by Sonac » 27/10/19 14:45

My 2 keeps draining its battery over 2 days. Very irritating.
Thought it was my dashcam at first which has constant power. Disconnected it and the drain was still there.
Thought it was my alarm next. So I found the alarm power and tested the current. It was using about 10mA which is fine.

Disconnected the negative battery terminal and put my multi-meter between that and the battery. Saw a huge 0.75A of current.

Started taking out fuses one by one. None of the fuses under the bonnet made a difference.
Went to the engine bay and pulled my first fuse which happened to be EFI. Current dropped to about 35mA.

I haven't been able to make it draw the 0.7a since. I tried starting the car. Locking the doors etc. Just won't do it anymore.

Anyone know what could be causing this drain? I didn't actually have view of the multimeter when I pulled the EFI fuse. I walked around the car to see it. So its possible it dropped on its own before I pulled the fuse.

Really stuck on this one! My car is too far from my house to trickle charge.

I'm having to jump start it every time I drive it!



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MR2DI4
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Re: Parasitic battery drain. Possibly EFI

Post by MR2DI4 » 27/10/19 20:57

35mA is bang on normal. Wouldnt really have suspected an ECU but if you can find a spare its like a 10min job to swap it. These cars are getting old now and if you plan on keeping it you should have a spare anyway i have two. The alternator is the other thing permanently connected to the battery and can cause issues.

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Re: Parasitic battery drain. Possibly EFI

Post by Sonac » 28/10/19 12:06

I just think its weird that the fault in intermittent. I checked the voltage when the car was running. Alternator is putting out a healthy 14.6 volts. And the alternator was only replaced a few months ago. I know for certain its not a fuse under the bonnet. I'm not entirely convinced it is the EFI since I didn't have view of the multimeter when I pulled the fuse. Like I said, could have dropped while I was walking around the car.

I hate electrical issues.

I have a whole 3SGTE out a GT Four in my attic including the ECU. I want to try and fit that at some point. I know it goes into limp mode without the charge cooler pump and level sensor but someone on here made a circuit to bypass it. Bye MAF!


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Re: Parasitic battery drain. Possibly EFI

Post by novinno » 28/10/19 17:09

Take the bulb out of the boot light. It may not be going off when you close the lid.

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Re: Parasitic battery drain. Possibly EFI

Post by MR2DI4 » 28/10/19 19:29

novinno wrote: ↑
28/10/19 17:09
Take the bulb out of the boot light. It may not be going off when you close the lid.
True the bulbs are nasty on current drain, also any of the interior bulbs that still stay on or switched on permanently.

My recent really high drain was caused by my Glovebox bulb, a modification made years ago because the MR2 unbelievably did not have one fitted. Things changed over time and sometimes the switch didn't turn off the bulb. Hard to spot the bulb still on with the glovebox door closed ! a bit of foam tape where needed and you can just see it switch off now before the door fully closes.

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Re: Parasitic battery drain. Possibly EFI

Post by Sonac » 09/11/19 16:13

Boot light is a small LED I fitted so I doubt that's draining it. I can now confirm its not EFI. I finally had a chance to do more testing yesterday and I pulled more fuses including EFI which didn't drop the current.
So its something on the interior fuse box.

Interestingly enough I think its the door side markers. I noticed sometimes my door doesn't shut perfectly and they stay on. I think that could be the issue. The door sensors dont work well on my car at all.

Will see how it goes now I pulled the bulbs out of those! I actually had my dome light turned off rather than on doors so I wouldn't have known. I only got the car at the start of the summer so i've had no need for the dome light until now when its getting darker.


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Re: Parasitic battery drain. Possibly EFI

Post by S81933 » 09/11/19 19:19

I've had that problem in the past; if a door doesn't close fully, the door side marker and possibly the interior light would stay on and I'd have a flat battery after not too long. Just check the door shut lines when you close them to make sure they've shut completely.

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Re: Parasitic battery drain. Possibly EFI

Post by MR2DI4 » 09/11/19 21:03

The door switches can be removed and cleaned. They mainly give you alarm problems if they are not right.

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