I've been experiencing a problem over the past couple weeks with being unable to start my 2010 TSX Tech intermittently. The car's been pretty rock solid for me since I bought it in 2009. However, I have been unable to start the car in the morning for the past 2 days without jumping it. I also had to jump it 2 additional times before that, both times having just started it to park it outside the garage for a short while. I had noticed a few weeks ago that sometimes it seemed like it would take longer for the engine to turn over and get started. My first thought was the battery (3 years old), but I've had it checked by 2 different shops and it's showing as fully charged and plenty of CCA (~470/500). And it starts just fine multiple times in a row when I have taken it to these shops. When I am starting it and it won't start, there is just a rapid clicking sound and the instruments flash rapidly and the engine doesn't catch. Once I hook up my jump starter to the battery, then I am able to start the car. I also noticed that the past 2 mornings my stored seat settings have been lost and I have to re-enter the radio code in the nav system. Does that indicate a battery dying overnight? I have been googling around and seeing that perhaps this is the starter. Does this sound correct? Could the battery actually be draining over night but then appears fine by the time I get to the shop? Any ideas would be much appreciated.

 

Symptoms indicate the battery is weak, poor connection to battery, or damaged section of battery wire. It could be ground side or positive side problem. W/0 testing you can't find the problem. Multi-meter and some voltage drop tests are necessary.

good luck

 

I tested the battery last night with my multimeter at 11:30pm and got ~12.69. This morning at 7:30 it was 12.62 and at 8:30 it was 12.5. I didn't touch the car or turn it in on between these readings and it started fine when I left for work. I don't get it, it seems very intermittent. The previous 2 nights where it didn't start in the morning, the car had sat longer - from maybe 6:00pm to 9:00ish the next morning.

 

How cold is it where you are? Batteries don't like cold, ie below 50° makes mine slower to crank. It will get replaced early, after only slightly more than 3 years.

Testing a battery w a multi meter doesn't really tell you much. Without a load, its not a meaningful number for starting.

 

This started when it got colder here. It's in the low 50's in the mornings right now. I don't have any other way to test it at my house.

 

Also, as a follow-up. When I called the dealer inquiring about setting up an appointment, they mentioned they have seen the HFL module going bad causing battery drain when the car is off. I have seen other threads about this as well for TLs/TSX/etc. I can't seem to find any guides about where the HFL is located for 2nd gen TSXs and how to disconnect it. Does anyone know how to do this? I'd like to try unplugging it myself before spending $155 for the dealer to diagnose it. I also ran the diagnostics on the Nav unit and all boxes showed green status even the HFL, not sure if that means anything.

 

Search in this forum for a thread on HFL, will tell you much more than you need to know on where it is, how to connect, replace, etc.

 

Just FYI, it ended up being the battery in the end. Replaced the battery and all is fine now.

 

crankshaft sensor

 

I am having the same problem pretty much. I dont think it’s the actual battery itself, it’s barely 2 years old.

The problem starts with the navi needing the code, then seat setting get deleted.

what I don’t understand is the car had completely lost power a few times, but every time except once, if I open and shut the door once or twice the power comes back on and the car starts. Once the battery was drained completely and started over being jumped.

why would opening and shutting the driver door make the power come back. I also noticed that if I don’t use the key fob to unlock the door and use the key itself, the Issue doesn’t happen as much

 

general rule when car needed a boost to start is to test the alternator and battery