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Discussion Starter #1
About 6 weeks ago I went out to drive my CX-3 and I could not get into the car. I had to use the key to open the door. Needless to say, the car did not start. I hadn't driven it for maybe 2 days, but that should not be a problem. My multi-meter read about 3V on the battery. My first thought were that I left some light or door open. I have the rear hatch light off all the time so that was not the issue. The dome light or the map lights were also not on(dome lights were also set to OFF(as apposed to the center monitor position.) So I jump started the car and charged the battery up.

The alternator seemed to be working as the voltage rose to nearly 14V and stayed there. I then went to an auto parts place where they used a device to test the alternator for free(must be they want to sell you the new alternator.) No issues here.

So I bought a new battery, seeing that this one had gone through a couple of long discharges as a result of "lights on" issues. I bought an Optima deep cycle battery and went back to life. A day or two later the battery was reading 3V and I had to recharge it!

Since the fuse in my multi-meter was dead, I placed a 10 ohm, 10 watt resistor in series with the battery and monitored the voltage drop on the resistor. It was baselined at 700mA.
Seems a bit high, but that said, it should not have drained the battery to 3V in a 24H period. While monitoring the current draw of the car I unplugged the fuses (one at a time), both under the hood and under the drivers side dash area. The current draw was unchanged. I did the same for all the relays under the hood with no change of current draw.

I slowly allowed my car to sit and monitored the voltage on the battery for a couple of days without driving it. The battery voltage was constant at about 13.7V - 13.9V. ZI proceeded to leave it over night and then for the next three weeks having no issues.

Now, just a 24h untouched I was again surprised by a dead battery. Currently I am disconnecting the battery after leaving the car overnight out of fear of finding the battery dead a third time.

Seems to be a really, really intermittent problem here, and one that draws a substantial amount of current.

One odd tidbit was that the map lights three positioned switch was acting weird. The voltage across the lights was 0V when the switch was in the OFF position, 12V(or battery voltage) when in the ON position, but 6V when in the CENTER-MONITOR position. At night I could see a faint glow on the LED light(note: LED replacing the stock halogen light.)
Either way, this phenomenon did not play into the dead battery issue as this switch is left in the OFF position. The current draw did not change with the switch in the OFF or CENTER-MONITOR position.


Q: Any idea what the nominal current draw of this car is when off?
Q: Will the repair guy detect the problem, being that it seems intermittent?

Any help would be greatly appreciated!
Thanks!
 

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Edit: I apparently cant read and didnt realize you already got a new battery lol dont mind me.

Was the car purchased new or used and is there anything added to the 'sound system'. Ive seen many a times of people wiring capacitors to battery power just draining it non stop.Also check the new battery manufacturer date just to be safe. Alot of places keep old products on a shelf especially optima batteries since more of a niche product with fewer rotations on the shelf than a 'regular' battery.
 

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Discussion Starter #3 (Edited)
Little gray sticker on battery says 12/19 for date. Not sure if that's good or bad.
I may have found something, but have now run into a larger issue. The car won't start, even with the battery at full voltage and even when trying to jump start. This is NOT a battery issue though.
There are two flashing lights on the console when trying to start. The "turn on warning light" - flashing green, and the "security indicator light" - flashing red. The "emergency operation for starting the engine" does not work either. In other words the car is "bricked" as some would say about their cell phones. Is there a particular fuse or relay that might control the engine starting? This is all I did was remove and reinsert these components one at a time.

Both key fobs were tried and failed, so the odds of both batteries being bad is very unlikely. Both key fobs were placed very close to the START button.

This really is a bad hair day!
HELP!

EDIT: Diagnostic code is U0101 - Lost Communication With Transmission Control Module

I can't find out which relay or fuse correlates to this issue!
23545
 

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Discussion Starter #4
UPDATE:
Tried a new battery in one of the remotes. It made no difference. Didn't think it would.
Checked every fuse in the engine compartment (no issues) and checked all relays (no issues).
I can't even take the car out of park.
 

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Discussion Starter #5
UPDATE:
Car starting problem is fixed. Apparently there is supposed to be a 15A fuse in slot 17(AT Transaxle control system), AT standing for Automatic Transmission I am assuming.
Car starts normally when a fuse is inserted. Given that I was pulling/checking one fuse at a time it makes sence that given a empty fuse socket on slot 16 was where I placed the fuse back, instead of in slot 17(See photo below). Starting the car is possible without a fuse in slot 16 but NOT with slot 17! Whether I need on a fuse in slot 16 is questionable, but I now have one there!
23547
 
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