04 XC70 crank no start conditon

[pilsbury88]

Current fault codes:

SRS: 007C and 0084 (rear seats removed to replace fuel pump)
CEM: 1A57
RTI: E003

This car has already had Xemodex CEM service done in 2001. This car does not have a fuel pressure sensor on the fuel rail. The fuel pump recently developed a leak out of the top Flange. The plastic had developed a micro crack, so the fuel pump needed to be replaced. The car still ran, but would take an extra second to start due to fuel pressure loss. I parked the car (with about 1/4 tank of fuel remaining) for about two months while I finished another project. When I finally tried starting the car to move it and replace the fuel pump, it would not start. It would crank for a while, but the battery was pretty weak from sitting unused. I charged the battery and replaced the fuel pump assembly. The car would crank but not start. There was no fuel pressure at the fuel rail Schrader valve. Fuel pump fuse is good. Fuel pump relay is good (tried swapping with other relays). I am getting no power on any terminals at the fuel pump connector with key on. Fuel pump relay Terminal 5 at the CEM has power with the key on. Fuel pump relay Terminal 3 at the CEM has good continuity to fuel pump connector pins 1,3, and 5. I have a scan tool that can read some live data. The fuel pump relay PID is always OFF, even during key on and cranking. It seems to me that the ECM or CEM is not commanding the fuel pump relay to activate for some reason. Is there any other diagnostics I can do to remedy this? Am i missing anything? Any help or guidance is greatly appreciated.

[jonesg]

2 months could allow corrosion at the ecm terminals and it does seem theres a com problem between ecm and cem?
I would try removing the ecm to probe continuity and check for green goblins.

[DavidE7]

The fuel pump operates for about 5 seconds when the key is turned to position 3 and then it turns off. Have another person turn the key while you probe for pump voltage at the connector.

I would also try starting spray just to verify that the spark and compression are still good. Just enough spray to catch for a second or two, not enough to cause a backfire or other problem.

[Vova585]

Your problem is not simple. It is hard for someone to follow along without making notes and seeing diagram. I doubt you will find answer here since someone will have to invest significant amount of time to figure it out.
I see 2 possible ways moving ahead:
1) tow to the dealer and pay for diagnostic service. It will cost usually 1-2 hours of labor plus towing. Volvo towing program covers first 25miles to dealer for free(as far as I remember, might be wrong here). Will cost you likely around $500 and you will know what is going on. You will have your hands clean and able to go to work.
Option 2: you invest in vida/dice clone($150+ headache to make it run), get yourself 1 month subscription to alldata diy($25) and this way you will see exact wiring diagrams and see theory of operation.
I think that you did a great investigatory work. But without wiring diagram and access to a capable tool it will be hard to move forward. (Is it immobilizer? Can you see with your tool if it is blocking the fuel delivery or not? )
P.s. if you next to State College PA, can ask Ivan from Pine Hollow auto diagnostic to look at your car.

[pilsbury88]

The fuel pump operates for about 5 seconds when the key is turned to position 3 and then it turns off. Have another person turn the key while you probe for pump voltage at the connector.

I would also try starting spray just to verify that the spark and compression are still good. Just enough spray to catch for a second or two, not enough to cause a backfire or other problem.

Confirmed the car will run on starting fluid. I expected to see power at the fuel pump for longer than 5 seconds, so I tried your method. I DO have power at only pin 5 on the fuel pump connector at key on, but only for about 1 second.

[pilsbury88]

Your problem is not simple. It is hard for someone to follow along without making notes and seeing diagram. I doubt you will find answer here since someone will have to invest significant amount of time to figure it out.
I see 2 possible ways moving ahead:
1) tow to the dealer and pay for diagnostic service. It will cost usually 1-2 hours of labor plus towing. Volvo towing program covers first 25miles to dealer for free(as far as I remember, might be wrong here). Will cost you likely around $500 and you will know what is going on. You will have your hands clean and able to go to work.
Option 2: you invest in vida/dice clone($150+ headache to make it run), get yourself 1 month subscription to alldata diy($25) and this way you will see exact wiring diagrams and see theory of operation.
I think that you did a great investigatory work. But without wiring diagram and access to a capable tool it will be hard to move forward. (Is it immobilizer? Can you see with your tool if it is blocking the fuel delivery or not? )
P.s. if you next to State College PA, can ask Ivan from Pine Hollow auto diagnostic to look at your car.

This is a backup family car. Transportation and dirty hands are not a concern. I find it difficult to stomach paying someone else to fix my vehicle and there are three P2 wagons in my family, so if acquiring VIDA is the only way forward it may be a worthwhile investment.

[jonesg]

lets review, New pump, it isn't pumping or priming.
No power at pump terminals at key on or cranking.
I'm still suspecting ecm terminals after an extended storage .

You need the wiring diagram to trace the command wire from the ecm to the cem.
If that circuit is good then the suspect is the cem.
Could be water damage.

Yes you should get vida, especially with 3.
Get a laptop and interface all set up and ready to run.
https://diaglaptops.com/wp/

[pilsbury88]

lets review, New pump, it isn't pumping or priming.
No power at pump terminals at key on or cranking.
I'm still suspecting ecm terminals after an extended storage .

You need the wiring diagram to trace the command wire from the ecm to the cem.
If that circuit is good then the suspect is the cem.
Could be water damage.

Yes you should get vida, especially with 3.
Get a laptop and interface all set up and ready to run.
https://diaglaptops.com/wp/

Only power at fuel pump connector is on pin 5 for 1 second after key on. Fuel gauge is working. Only about 1/4 tank in there. I let the fuel level get pretty low anticipating this repair. It could be as simple as i messed something up when installing the pump, fishing the wires through to the driver side level sensor. I haven't pulled it all back out to look. I'm unsure how the fuel pump system works. Maybe the CEM looking for some kind of signal from the pump before it will provide power? Since this car doesn't have a fuel pump module or pressure sensor on the rail, I would think the CEM would send power to the pump all the time with key on. Which may be the case. If it is, as you said it's likely a ECM/CEM issue. I have emailed xemodex with all the info I have and all they said was the codes are inconclusive but make them think it's not a CEM issue.

I now have some additional codes.
3A05 fuel pump signal too low (CEM)
4A33 and 4A37 fuel level sensor signal too high/missing (REM)

These codes only showed up after cycling the key 5 or 6 times with the fuel pump unplugged to check for power there. So I imagine that's what triggered them.

I can pull the ECM/TCM and have a look for corrosion. I can pull the fuel pump and level sensor to have a look at the connections inside the tank. I can also add a few gallons of fuel to the tank to see if that makes a difference. Thanks for the link to VIDA stuff. I was kind of going down a rabbit hole starting to figure out how to get into it.

[pilsbury88]

ECM and TCM terminals are corrosion free and quite lovely, on both component and harness side.

[jonesg]

ecm terminals looks good.
Do you have the original pump, it might make a good test to plug it back in.

That 1 second pulse at the pump is prime .
You can try feeding 12v directly to the pump.