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Just returned from overseas after six months. Vehicle was running just fine before it went into hibernation. Vehicle was on a battery maintainer but power was lost at the house and the circuit tripped leading to a completely dead battery. Just replaced the battery and now I get a crank but no start condition. I hear the fuel pump(s) priming with door open.
Current codes are P0344, P0349, P0685, and P0687. Cleared the codes but the P0687 remained. The other codes returned after attempting to start vehicle.
I find it unlikely both camshaft position sensors failed, especially with the addition of the other generic powertrain faults. I don't have any advanced diagnostic tools (e.g., PIWIS, etc) and I don't even know where to begin troubleshooting. A thorough search didn't reveal much. Help!
Update: actually I don't think I hear the fuel pumps priming. Re-checked the torque app and it's saying fuel rail pressure is 4.4psi. Either that's erroneous or if correct, maybe something else? I checked fuse #13 under the hood and it's intact.
The fuel pump should be priming nearly anytime you open the driver's door. I guess there is 15 seconds timeout, meaning if you will open the door again within this 15 seconds timeout it will not prime the fuel. I may be not fully correct on 15 seconds timeframe, but it's fairly short.
But again - codes for camshaft position sensors for both banks. To rule them out the oscilloscope should be used.
Understood, and yes, I gave it a little time-out period before opening the door again and I'm not getting anything.
I'm leaning toward a fuel issue at this point. The cam sensor codes might be getting thrown after extended periods of no start while cranking for a good 15 seconds of so.
Is there a fuel test port so I can hook up my gauge? Likewise, is there a relay? I can't find anything when searching. All the results are from 955/957.
Last edited by 10001010101; 12-19-2023 at 07:58 PM.
UPDATE:Diagnosis is failing fuel pump relay and/or corrosion at terminals.
Started pulling the under hood relays and testing them. I surprisingly could find nothing on the intertoobs that identified which of the relays correspond to which systems. The gray one with the large "614" label one was first in the chute. It surprisingly tested out good at the onset. I didn't just do the ol' click test. I ohmed it out and tested resistance but noticed it was a little inconsistent in opening and closing the circuit with power applied off and on repeatedly...meaning it didn't do it every time. There was also a noticeable rattle internally and some slight flaking at the terminals and in the junction box where it seats. I peered underneath the junction box where the wires run up to the terminals and everything looks good with no signs of corrosion or water intrusion anywhere. Re-seated the relay, opened the driver door and immediately heard the fuel pump prime. She started right up and I got her legs stretched and off to the gas station after six months of sitting. BTW, the pending camshaft sensor codes disappeared with no CEL on the display. Historic faults still in memory but I expect those to clear after a few drive cycles. Maybe this thread will help someone in the future.
Last edited by 10001010101; 12-21-2023 at 06:22 PM.
12-19-2023, 06:16 PM
Crank - no start
