ScanGauge II drawing 50 milliamps when off.

I have had a parasitic drain that started to kill the battery quicker and quicker. The battery is a Die Hard Platinum group 35 that is just over 5 years old, but it tested out both times I had it checked. When driving, truck charges to over 14 volts at the battery and on the ScanGauge. Lately, the truck would not start if it sat for a day. I confirmed that the battery was low, under 12 volts, each time the car would not start, checking the battery before starting. Using the multimeter, I checked for drains between the negative terminal and the negative clamp. After removing known small amp drains, I still had 80 milliamps coming off of it after the truck went into sleep mode. If I unplug the SCII, it drops to about 25-30 milliamps. If I plug it back in, it goes back to 80. Searching around, I have found where a person with a 4runner had the same issue, but no solution. Has anyone else checked to see what kind of drain the Scan Gauge puts on your system?

 

I don't have a Scangauge but 80ma seems like a lot for the the SG in sleep more. SG claims 1-2ma but from what I've heard 10-20ma is what people are getting.

I have an UltraGauge, both current & older versions. I've never measured it's current draw during sleep but for the 8 yrs I've been running the UG I've never had a problem with it killing my battery. I'm pretty sure my aftermarket alarm draws more current than the UG.

The UG has different sleep modes it can be set to if a user does have an issue with excessive battery drain. Maybe check to see if the SG has a similar setting?

 

Thanks for the quick reply. I just got off the phone with ScanGauge and I am going to send it in and have them check the cord and the unit. I hope that’s the issue and not something going on in my ECU!

 

I seem to recall a thread in the last year or two where someone had a short in the OBDII connector. People speculated that the gauge plugged in was drawing to much current but I think there was a problem with the connector or wires. You might try searching for that thread and/or inspecting the OBDII connector.

 

Yup. Melted OBD connectors have been reported. I cant say Id buy one anymore. A year ago I wanted one pretty bad, but now, I think Ill pass.

 

Interesting. I will double check that in the morning. Scan Gauge did say to send in the unit and the cord, so they might know there is an issue with the connection.

 

Don't know if the melted OBD port is related to this but years ago people with ABS on 1st gens were having issues with the light turning on with SG or UG. Some auto manufacturers like Ford & Toyota used different pins for different functions & when a SG or UG was connected & scanning for protocol funny things would happen. UG now has a force protocol option & I believe SG does too.

https://www.tacomaworld.com/threads/abs-light.111669/#post-2153065

UG also sells an isolation cable for further safety. I don't have ABS so never had an issue & never needed to use the isolation cable or force ISO-9141 protocol option.

https://ultra-gauge.com/ZC/index.ph..._id=49&zenid=3c613637b4ca19185e07ab19d978fd5d

 

Found this thread on here. Worth investigating https://www.tacomaworld.com/threads/scangauge-2-broke-my-obdii-and-is-causing-problems.566297/

 

I think that's the thread I remembered...more recent than I thought, but it sounds like his issue was related to a bad ground so maybe not too much use for you.

Maybe other people can test there current draw of there scangauge.

The other thing is if the battery is just old and almost worn out then even a little current draw will deplete it enough to prevent it from cranking.

 

Well I'll be damned I've got to pull my scangauge out right now.

 

How do i check what drain my scangauge is doing?

 

Dr. Z. You are correct. I have Blue sea fuse block in the back of the truck for everything that runs out of the camper. I have a few ways I can send power to the fuse block, one is always on, one is switched, and the other is a jumper cable that runs from the Ark Pak when it’s installed. That set up had a 40 mA draw when I started checking, so I disconnected it and the draw dropped down to 80, which is when I found the scan gauge issue. I think the effects of both drains finally started taking their toll on the battery.

 

Disconnect your negative cable from your battery, turn your multimeter to measure amps or milliamps, put one lead on your battery terminal and one on the disconnected cable. The number you see is what your truck uses when it’s off. Be sure to let the truck sit for a few minutes to go into sleep mode. Now, disconnect your scan gauge, shut the door and let it go into sleep mode again. Check again. The change in your readings is what your scan gauge was using.

 

More info from searching around. I have to remove the cable to send it back to Linear Logic, but I have it routed behind the dash for a clean install. If the cable from the obdII is compromised or bent somewhere, that could be causing the draw. There were a few instances on the internet of that happening.

 

As more antedotal evidence I had an SCII in my Miata for a number of years, then moved it to our '04 Highlander a few years ago. I also have another in my '13 Tacoma for about 4 years now.

Both units were bought used, and have upgraded software from ScanGauge, but original cables.

Never a problem with either of them in any of the vehicles.

 

I personally have 3 of them. One has been in my Tundra for 70k, my FJ for 90k and 1st gen for 50k. And 3 others in my extended family's vehicles. They all stay plugged in 24/7 for years. Not a single issue.

 

Is it a rebadged Odyssey? If so I would expect it is at the end of its life unless you have been using one of their chargers once a month to give the proper charging profile they need. Our alts dont provide it. You can try and recover it by leaving headlights on till battery hits 10v then give it 40a inrush at 14.7 with a smart charger that has the correct charging profile. Let the battery settle for a day and if you end up at 12.8v then it is at 100%. Odyssey says you can do this multiple times in a row and possibly get it back up too 100% capacity.

 

That's great. I dont wanna risk potential electrical issues caused by these things, that some posters here have expressed in the past. And frankly, I dont care enough to know the info they offer.

 

Just to clarify for anyone following. I have had a scan gauge hooked up in this truck for several years, at least 6, maybe 7. The first one had an issue with the LCD screen, and it was replaced. I never checked the draw on the truck because the truck always started. In 2016, I added the fuse block to the back of the truck, and it was only with the combination of the power going to the fuse block and the scan gauge draw that my truck started having issues starting, and thus I started checking for a parasitic drain.
Pickledpigs, you are correct. It is a rebadged Odyssey, and if what you are saying is correct, I’ll probably be getting a new battery soon. I also have a group 31 in the Ark Pak, and it just took a crap too.

 

I'll add that you don't want to exceed the max current listed on your multimeter. Most have fuses that will blow. For example my multimeter has two settings for current measurements, max 200mA and max 10A. Just the interior light when you open the door could go over 200mA. A small 3.4 Watt bulb will draw 200-250mA. Accidentally stepping on the brake pedal will put you over a few Amps.

Start with the highest setting on your multimeter. Some require you to plug the lead into a different hole on the multimeter. Roll down the window and pull the scan gauge without opening the door, especially if you are using the lower setting.