2005 XC70 Cranks but will not Start

[hoonk]

Fuel pump solenoid does comes on, I can hear pump(s) working,

Solenoid? If you have a fuel pressure sensor on your injector rail there is no solenoid or relay for the fuel pump on your 2005. There is a controller, but it's electronic, and makes no noise.

Your fuel system electrical items:

Fuel pressure sensor, ECM, fuel pump controller (PEM), and the fuel pump. The controller runs the fuel pump as needed to maintain the correct fuel pressure. The fuel pump does not run at full speed all the time like earlier systems did.

Controller's can go bad, early cars had them mounted to the right side of the gas tank subject to corrosion - later they were moved to under the back seat.

[kef]

kef, do you need to go back and check the work on your new fuel pump install? I don't have experience (yet) with the fuel pump operation but maybe something didn't get hooked up correctly?

X: I think I will do that. I am pretty sure that I reconnected the 2 tubes and wirings as before (on the right side of the tank). I also made sure that the spring-loaded fuel inlet in left side of the tank is placed properly with the single wiring (level sensor) connected. I can hear the pump(s) whirring during and post ignition. I'll see what I can do... and zone in to see if the pumps are 'trying' to push fuel out... Yes, carefully!

Interestingly, taking the seat back rests off is most of the work.

Thanks!

[kef]

Solenoid? If you have a fuel pressure sensor on your injector rail there is no solenoid or relay for the fuel pump on your 2005. There is a controller, but it's electronic, and makes no noise.

Your fuel system electrical items:

Fuel pressure sensor, ECM, fuel pump controller (PEM), and the fuel pump. The controller runs the fuel pump as needed to maintain the correct fuel pressure. The fuel pump does not run at full speed all the time like earlier systems did.

Controller's can go bad, early cars had them mounted to the right side of the gas tank subject to corrosion - later they were moved to under the back seat.

Hoonk: Sorry, I meant to say "relay" rather than solenoid. I could activate the relay via DICE as ON/OFF. Thanks for the correction and additional info!

Now, I'm thinking the fuel pump controller (PEM) is probably the culprit. And yes, on mine the PEM is outside right close to fuel filter. Frankly, I was hoping for some interaction with the PEM using DICE to troubleshoot its functionality. Not sure what I can do really. At least, I can start by disconnecting the electrical connection, clean and re-seat it. So, The PEM as source of my problem is my next plan of action.

Thank you!

[hoonk]

I could activate the relay via DICE as ON/OFF.

The only relay shown on a wiring diagram of the fuel system for a 2005 with a PEM and a fuel pressure sensor on the injector rail sends power to the turbo control valve and the heater in the pcv system. There is not a fuel pump relay shown. Earlier cars ~2002? do have a fuel pump relay.

Volvo has an extension wiring harness to be able to move the PEM inside the car, under the seat.

[kef]

The only relay shown on a wiring diagram of the fuel system for a 2005 with a PEM and a fuel pressure sensor on the injector rail sends power to the turbo control valve and the heater in the pcv system. There is not a fuel pump relay shown.

Hmmm. I can actually activate the Fuel Pump Relay via DICE with a START and STOP activation. As a result, I can hear the pump(s) come on and off. This is a CEM operation. I have attached a photo. Not sure if it will show up in the post...


So... I looked into the PEM, and have some interesting observations.

- I found a cut on the rubber sleeve of the wiring harness.

- Looking at the cut closely, I could see some chaffing of 2 of the wires (white, and white+black). In fact, the 2 wires appear to be touching (shorting)

- I then separated the wires, cleaned up the contacts, plugged it back in
...

STILL WON'T START.

Interestingly, the cut looks like it was made by a rodent (chipmunks are rampant in my driveway). I had actually seen them scurry under the car in the past - destination unknown!

My only thought now is that the shorting may have caused a damage to the PEM. Please field your inputs...

Any recommendations for where to get a used PEM? Unfortunately, there are no 'pick your own parts' in upstate NY (Saratoga County)

[I have attached some images... not sure if they show up in the post]

Thanks!

[Leto Atreides II]

Erie probably has one.

[Xfingers]

Hmm, kef, I have little to no understanding of the fuel delivery system so sorry I can't be much help. Those damaged wires didn't look good. Can you hear the fuel pump making a whirring noise when you turn the ignition key to Run, before turning to Start? Anyone know if this would confirm the PEM is working correctly?

[kef]

Leto...: Thanks! I've ordered the PEM from Erie. Very helpful guys!

Xfingers: Yes, I can hear the fuel pump before and after cranking. That's what so odd about the fuel delivery problem -- If I can hear the pumps whirring (with old and new pump assembly), why can't I see a single drop of fuel coming out to the filter? Is it because only one of the two pumps is working? Is there a signal the PEM needs that it is missing? What signals does the PEM need?

If the replacement PEM (used from Erie) does not resolve the problem, I may end up taking off the pump and closely watch the operation.

[kef]

Success!

Happy to say that the new PEM (from Erie) resolved by starting problem.

Thank you all for your support!

To summarize:
The problem: The engine cut-off after about 2 seconds, and could not start, but could crank.
The fix: New PEM (used from Erie V)
Other work performed to address the problem (but not a fix):
- Replaced antenna ring (VIDA/DICE reported it as a problem)
- Replaced fuel pump assembly (BOSCH)
- Replaced crankshaft position sensor [I think this CEL came on because of battery drain]

I think due to a short of the wiring at the PEM (see pictures in my previous posts), the PEM was malfunctioning even though I could hear the fuel pump(s?) operating. My only guess for no fuel pressure in the line was that one of the pumps was probably not operational. I'm surprised there were no messages displayed, no CEL or no info on VIDA/DICE to troubleshoot the PEM problem.

Cheers!
-Kef