Hello all, im posting this for a friend of mine.

He just had delivered a 2010 base model (about 50k miles on the clock) that had been in a wreck. Front crash bar is dented in pretty good on the driver's side, and the drivers airbag did deploy.

We did some research and based on what we read, we figured the airbag module would be telling the pcm not to turn the fuel pump on. However when we turn ignition on, the fuel pump relay clicks temporarily (I even tried manually bypassing it) and I checked that the 10A fuse in the underhood fusebox is also good.

My friend swears he can hear the pump kicking on when ign is turned on, but I can't hear it personally. We don't have 0 pressure at the rail, but it is definitely super low (he's getting a fuel pressure tester tonight to see what its at).

Does anyone have any idea or experience with this? Is there a secondary fuse or relay for the fuel pump that we need to look at downstream of the underhood box? I'd be surprised if the fuel pump is bad after only 50k miles but I guess its not impossible.

Additionally, the drivers side latch doesn't release when pressing the button (interior or exterior). i can hear the latch making noise when the button is pressed, but it sounds very weak. Was this a common issue with these cars? Again, just surprising it would go bad after such limited use.

 

First thing the airbag module has nothing to do with the ECM telling the fuel pump to turn on…don’t know where you read that…have you removed the fuel pump relay and jumped terminals 30 and 87 which is the load side contacts…the fuel pump should run continuously…if not you need to check for a voltage drop between battery positive and connector X459 which is behind the rear left tire wheelhouse panel…the ground side should be checked as well…there are 3 connectors between the relay and the fuel pump…you can try going to X459 and give the pump power and a ground and see if it runs.

 

 

I read it on a (admittedly older) thread here on the CF where someone had bought a wrecked C6 and couldn't get it to run. Someone had said that the Airbag module would send a signal (until it was reset) to the PCM to not activate the FP relay to reduce the chance of a fire in the event of a collision. It seemed plausible and I couldn't find anything anywhere else denying it.

We were on the side of the road a few blocks from my friends house, so we didn't have a bunch of tools available. I didn't jump the pins with a jumper wire (or paperclip) but I did take the cover off of the relay and manually activated it. The PCM was turning it on like normal anyway, but I wanted to make sure it stayed on.

Thank you for the picture! We'll start there. Unfortunately he's out of town for a couple of weeks so it'll be a minute until we can work on it, but I'll update this thread as soon as he gets back!

 

Without starting the engine the pump will just run for 2 seconds and shut off unless it sees a crank sensor signal and then it will stay running...I've done bypass testing of the crank sensor with a 12 volt test light and if a crank sensor signal is simulated the pump will turn on and you can hear the fuel injectors turn on.

 

So this is interesting. Got out to my friends house to help diagnose the pump issue. Double checked fuse, voltage through the fuse, and also that there was voltage on the common pin at the fuel pump relay. All checked out.

Hooked a gauge to the fuel rail and key on jumped to 42psi. Low, but I figured we could try starting it to see what happens. Car fired right up. Fuel pressure jumped to 62psi as soon as it started Cranking as well.

Let it idle a bit, then shut it off. Started it a few minutes later and took a bit of Cranking but finally fired. Drove her around the block and she drives fine.

fuel that came out of the rail was yellow and definitely a bit aged, but not terribly. Going to try to burn through the tank and refill with some good premium and a bottle of techron. Hopefully that helps with any further issues. Just crazy that it took a week of sitting in his garage and the minute I show up it decides to start.