Keyless start

[noonegobo]

Hey all,
My 2019 Civic RS has been having problems starting unless the key is physically touching the start/stop button. When the car is off it seems to loose all power. I’ve had the engine battery and the key fob battery replaced so I’m not really sure why the car isn’t recognising the keys.
Does anyone have a fix for this?

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[DRUSA]

When the car is off it seems to loose all power.

As in, when you let the car sit with the key out of the car the battery will die after a few days?

You need to see if there are any body DTC's and then start checking for a parasitic draw condition on the battery, looking for a control unit keeping the system alive when it is not supposed to be.

This could be a number of things: a parasitic draw from a control unit, a bad keyless access antenna, a blown 10A back up fuse in the underhood fuse box (but you would not have a radio either), a bad battery in the key fob even though it was replaced with a whole new unit maybe it has been sitting on the shelf and died? Lots of things.

 

[sillyrabbit]

Have you tried your second key? Does it have the same issues? This might help you figure out if it's a key issue or a car issue.

 

[noonegobo]

As in, when you let the car sit with the key out of the car the battery will die after a few days?

You need to see if there are any body DTC's and then start checking for a parasitic draw condition on the battery, looking for a control unit keeping the system alive when it is not supposed to be.

This could be a number of things: a parasitic draw from a control unit, a bad keyless access antenna, a blown 10A back up fuse in the underhood fuse box (but you would not have a radio either), a bad battery in the key fob even though it was replaced with a whole new unit maybe it has been sitting on the shelf and died? Lots of things.

I replaced the car battery and remote battery this morning so that eliminates any sort of battery issue.

The car does not have any sort of power regardless of where the key is. It only has power when the car is started via the remote method I mentioned above.

Will have a check on the fuses. Thanks for your suggestion.

 

[noonegobo]

Have you tried your second key? Does it have the same issues? This might help you figure out if it's a key issue or a car issue.

I used both the main key and backup key. Doesn’t seem to pickup anything. I can’t even lock or unlock the car.

 

[shoegazer]

Since there is an actual Honda tech on the thread; I'll defer to them ultimately.

But if you check the fuses and find they are all 'good'; I'd do the battery disconnect/reset procedure. It's basically a reboot. Many weird problems have been 'solved' this way.

Good luck.

 

[DRUSA]

I used both the main key and backup key. Doesn’t seem to pickup anything. I can’t even lock or unlock the car.

This sounds like a blown back up 10A fuse. When the cars come off the truck from Honda they act the same way until you put in the PDI fuses. You have a kangaroo market car so idk if fuse location is the same as ours, but if you read the underside of the fuse box cover in the engine bay it should be labeled "BACK UP" and is a red 10A fuse iirc. Looking at a USDM wiring diagram, this is what I would check first.

 

[noonegobo]

This sounds like a blown back up 10A fuse. When the cars come off the truck from Honda they act the same way until you put in the PDI fuses. You have a kangaroo market car so idk if fuse location is the same as ours, but if you read the underside of the fuse box cover in the engine bay it should be labeled "BACK UP" and is a red 10A fuse iirc. Looking at a USDM wiring diagram, this is what I would check first.

Wow, it worked!! I replaced my backup fuse and everything is in working order. However, I also discovered why the fuse had went off in the first place. The backup fuse went off right after I plug my ktuner into the obd port. Would there be some sort of fuse for the obd port that I can check?

 

[DRUSA]

Wow, it worked!! I replaced my backup fuse and everything is in working order. However, I also discovered why the fuse had went off in the first place. The backup fuse went off right after I plug my ktuner into the obd port. Would there be some sort of fuse for the obd port that I can check?

It's like I do this all day or something lol. That back up fuse is the main power supply fuse for the DLC connector, so this is your "OBD port fuse" you are looking for.

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