Parasitic Battery Drain help

[Mighty Mouse]

After purchasing a brand new Toyota group 27 TrueStart battery, it’s not living up to its “TrueStart” claim.

I’ve only had my 2011 GX460 under two months and I’m fighting gremlins, check engine codes indicating misfire on cyl 1 and 3. I also have a battery drain as well. Brand new battery drains overnight and won’t start at all. Jump starts just fine.

Battery drain: measured 13 plus volts while alternator is charging. The only actions taken son fee at was a deep clean of the neg battery cable to fender ground. Also to note: I have also installed the Hamilton CarPlay unit and that might be a cause.

Check engine codes: P0301 and P0303. These only come on periodically just after starting engine. The engine runs rough so I can feel the vibrations. However, turn off truck, push start button twice to get in ign mode, clear the codes and power off. Start engine and no codes, engine running smooth.

I don’t know if these two issues are related, but I mention them in case they could be.

I’m jinxed I truly believe. I bought an 80 series triple locked 1994 Land Cruiser. I was able to drive it five months until it would not run properly when pushing accel pedal. Suspect I need an engine bay wire loom. It’s been down ten months now.

Bought GX460 to replace Land Cruiser (which I still have but intend to sell it) and right away I’m getting codes and dead batteries. I can’t get any good karma coming my way.

Thanks for reading, letting me whine just a bit, but hopefully you can supply experience based suggestions how I should proceed.

Thank you all

 

[Rednexus]

P0301/P0303 are misfire codes. Those can be any number of items. Intermittent rough running to me indicates an ignition (i.e., coil or connector issue), but it could be as bad as a blown headgasket, burnt valve, etc. It will require some effort to diagnose those. I'd first start by swapping the No. 1 and No. 3 coil packs to different cylinders (say 4 and 6). If you get P0304 and P0306 codes instead of P0301/P0303 codes, then you know it's the coils. If not, you'll need to dig deeper.

Regarding the parasitic draw, you can usually isolate those using a parasitic draw test. You need a multimeter that can measure at least 10 amps of current. You then disconnect the negative terminal on the battery and hook up one of the multimeter leads to the disconnected ground clamp and the other to the negative battery terminal. That will tell you the amp draw. It should be less than 50 milliamps. If your battery is dying overnight, it will be many times that. Then, with the doors shut, ignition off, and car locked, start pulling fuses and watching the amp draw on the multimeter. You can start with the underhood fusebox and then move to the cabin fuse box if you haven't found the draw. Checking the cabin box will require manually holding the dome light switch in the door jamb closed so you can lock the rig and have the dome lights off but still keep the driver's door open. The amp draw should immediately drop off when you pull the fuse for whatever circuit the parasitic draw. After that, you'll need to investigate that circuit to see what is causing the draw. Last time I had this issue it was the rear dome light assembly.

 

[Mighty Mouse]

P0301/P0303 are misfire codes. Those can be any number of items. Intermittent rough running to me indicates an ignition (i.e., coil or connector issue), but it could be as bad as a blown headgasket, burnt valve, etc. It will require some effort to diagnose those. I'd first start by swapping the No. 1 and No. 3 coil packs to different cylinders (say 4 and 6). If you get P0304 and P0306 codes instead of P0301/P0303 codes, then you know it's the coils. If not, you'll need to dig deeper.

Regarding the parasitic draw, you can usually isolate those using a parasitic draw test. You need a multimeter that can measure at least 10 amps of current. You then disconnect the negative terminal on the battery and hook up one of the multimeter leads to the disconnected ground clamp and the other to the negative battery terminal. That will tell you the amp draw. It should be less than 50 milliamps. If your battery is dying overnight, it will be many times that. Then, with the doors shut, ignition off, and car locked, start pulling fuses and watching the amp draw on the multimeter. You can start with the underhood fusebox and then move to the cabin fuse box if you haven't found the draw. Checking the cabin box will require manually holding the dome light switch in the door jamb closed so you can lock the rig and have the dome lights off but still keep the driver's door open. The amp draw should immediately drop off when you pull the fuse for whatever circuit the parasitic draw. After that, you'll need to investigate that circuit to see what is causing the draw. Last time I had this issue it was the rear dome light assembly.

Rednexus. The parasitic info is valuable stuff. Your explanation is just what I needed. Thanks. I’ll report back after these howling’ Wyoming winds die down.

Mike

 

[Rednexus]

Rednexus. The parasitic info is valuable stuff. Your explanation is just what I needed. Thanks. I’ll report back after these howling’ Wyoming winds die down.

Mike

No problem! It took me a good 3 hours using that process to figure out my dome light issue, as the draw was only active if the light was set to "DOOR".

FYI we took our family vacation through Wyoming earlier this year. My 8-year old said the area around Lander was "the prettiest place I've ever been". It's a great state.

 

[Mighty Mouse]

No problem! It took me a good 3 hours using that process to figure out my dome light issue, as the draw was only active if the light was set to "DOOR".

FYI we took our family vacation through Wyoming earlier this year. My 8-year old said the area around Lander was "the prettiest place I've ever been". It's a great state.

I live North Central Wyoming in Sheridan. The Bighorns is where I adventure. I haven’t been down by Lander for three years or so. I’ll need to make that happen again.
Thanks again for getting me on the right path. Your steps put it all together for me.

 

[r2m]

Regarding the drain on your battery, I had the same issue. The cause was the very rear light was always on.
The reasons I couldn't tell my rear interior light was on:

1. With how my rig is built out, I can't see the light from the inside rear view mirror.
2. When I close the doors during the day, it's too bright and still can't see if the light is on.
3. Finally, at night, since the interior lights stay on for 30 seconds or so after locking the vehicle, by then I've walked away and notice if there was a light on.

You may want to check that ALL your interior lights or off after you lock your car.
Once I figured that out, my battery has been fine.

 

[Mighty Mouse]

Regarding the drain on your battery, I had the same issue. The cause was the very rear light was always on.
The reasons I couldn't tell my rear interior light was on:

1. With how my rig is built out, I can't see the light from the inside rear view mirror.
2. When I close the doors during the day, it's too bright and still can't see if the light is on.
3. Finally, at night, since the interior lights stay on for 30 seconds or so after locking the vehicle, by then I've walked away and notice if there was a light on.

You may want to check that ALL your interior lights or off after you lock your car.
Once I figured that out, my battery has been fine.

Thank you. I will test this evening. Fingers crossed it’s just that simple.

 

[alhounos]

3rd on the dome lights. There are lots of them (three rows plus door lights plus rock lights, depending on config) and they are all energy-hungry incandescents. I measured over one amp draw with the door open, IIRC. Even without the dome fuse pulled, the GX draws about 0.1 amps for a good 30 minutes after you shut the door, so avoid opening and closing the car frequently without driving it.

Even with these in mind, you're gonna need a battery tender if it's not your daily driver. It's just a high-drain vehicle.

 

[alhounos]

*even with the dome fuse pulled

 

[Rednexus]

The Toyota/Lexus spec is 50 milliamps of draw with everything of and locked. My rig draws just over that (~55 milliamps) which I attribute to aftermarket stereo equipment. With a fully-charged 50 amp/hour battery at 50 mA of draw, you should still have 12 starting volts after around 18 days of sitting. I've left mine sitting for around 10-12 days several times and it's always started right up.

If it's sitting for more than a couple weeks at a time regularly, a battery tender would be a good investment.

 

[Mighty Mouse]

The Toyota/Lexus spec is 50 milliamps of draw with everything of and locked. My rig draws just over that (~55 milliamps) which I attribute to aftermarket stereo equipment. With a fully-charged 50 amp/hour battery at 50 mA of draw, you should still have 12 starting volts after around 18 days of sitting. I've left mine sitting for around 10-12 days several times and it's always started right up.

If it's sitting for more than a couple weeks at a time regularly, a battery tender would be a good investment.

When talking about the open door, I’m dealing with P0301 misfire issues. But that’s another topic, but today I ran errands, four stops in total. On my last stop, I started the (2011 GX460 Premium) and it threw the 301 code. I have a Bluetooth OBD2 code reader and as I’m trying to sort all this out, I just clear the code, restart the engine and drive home perfectly fine.

But here is the part of this reply I wanted to ask about; While home I had the driver door open while reading codes, and then on my Hamilton unit it said, “Low voltage detected, please start engine.”

I tried but all I got was clicking. I had the door open about 10 minutes, but I also have the dome light switch set to off.

What is going on? Any ideas on this and/or the CEL issue would be appreciated.

 

[Rednexus]

If the battery itself is good and has 12+ volts, you may have a connection issue somewhere. It could be as simple as the battery terminals themselves or perhaps the main ground wire (which goes into the inner fender just behind the battery). I'd start with a fully-charged battery (i.e., put it on a charger, check that the voltage is at least 12.5 volts after charging - I have a small Noco Genius charger and love it), see if you get the low voltage issue again, and if you do start checking connections. All connections should be clean and tight.

Also if you have a normal lead-acid battery and it has been deep-discharged many times by a parasitic drain, it's possible the battery is no longer holding a charge. Most auto parts stores can test the battery for you, but you can also buy a tester (I have a $25 Amazon tester, Harbor Freight sells them for around $40).

For CELs - try swapping coil packs between cylinders (i.e, put the No. 1 coil on something like the No. 7 coil) and see if the code changes. If your PO301 changes to a PO307 issue, then it's the coil pack. If it stays a PO301 than it's something else.