RDX Weird Electrical Problem
 

I have a 2010 RDX SH AWD. Turned it off a couple days ago and it hasn't started since. The engine will crank, but no start. When I let off the key, the engine still cranks. I have positive voltage coming from the negative side of the battery. I've replaced the starter and battery with no change. Any ideas?

You need 3 things to start the engine - air, fuel, spark. (4th thing in some cars...proper grounding of the electrical system)

How many miles are on it? If you turn the key to the on position without cranking the engine do you hear the fuel pump priming? It's unlikely that your spark plugs all suddenly stopped working.

The RDX has about 100k miles on it. I can't hear the fuel pump when I turn the key on. The problem started immediately after filling up the gas tank.

I'm also getting codes 83, 77 and PO627 on the navigation screen.

Maybe ck the fuse for the fuel pump?

And look up the malfunction codes.

P0627 is a fuel pump issue.

Is there a fuel pump relay somewhere that could be bad? If so, where is it?

If this ends up being a fuel pump issue, you'll want to take it to your favorite mechanic. It's quite the messy, smell job. Not impossible, but messy all the way around.

Changed the fuel pump module, it started right up and ran good for 2 days, but now it's quiting again. Sometimes it starts, sometimes it doesn't.

Haven't been on here in a while but my electrical problems have started to surface again. Maybe its the weather.

I have lots of problems with mine shutting off as I come to a stop (red light). Crank it over and fires up again. Similar, but different than yours.

I replaced the ignition switch years ago and the issue went away for a couple of years. Back now but getting the dreaded P0237 so thinking it's a short in the sensor wiring. I've also had issues with A/C and other general electrical gremlins.

For little cost and if you have time and ability, I would suggest pulling relays and applying a small dab of solder to each metal pin. These cars seem to be very sensitive to relay connections and I did this years ago and aside from a recent bug seemed to remedy all of my stalling issues. This may not solve this particular problem but seemed to buy me a few years of reliability. Just a thought.