[jack129]

Hi everyone,
I have a 2006 E350 with PZEV fuel tank at about 138K mileages, still under the CA emission 15/150K warranty from MB. Car crank over but won't start, trying to trouble shoot if fuel pump has issue before tow over to dealer.
Right now, knows the following.
1. Checked fuse/relay in trunk, seems OK. Check starter relay in front under hood, seems OK, fuel line pressure is 0. Car will start for few seconds if spray some carb cleaner into the MAF.
2. Checked the voltage at the fuel pump behind driver side, no voltage, key fob turned to 2nd position.
3. Jumped the fuel pump relay on slot A on the rack (last/bottom one) (removed the relay, jumping pin 3 and 5 using wire), getting about 11.5V at the driver side fuel pump connector.
4. Checked the fuel pump relay on A (the other 2 pins of relay slot, forgot the number, 1? and 2?) this suppose to energize and create a charge to close pin 3 and 5 to deliver voltage to the pump, pin 1 and 2 together read 8V, not sure if 8V is correct? any one knows? Is the 8V suppose to be 12v? Pin 1 self give about 11.5v , and pin 2 is about 3V on itself.

So I would like to check why pin 1 and 2 on the relay slot only give 8V and it's not enough juice to close pin 3 and 5 or if this is normal. and where is this voltage coming from. Having a diagram / schematic would be helpful.
Please advise if you know what's my next time to check.

Thanks in advance!

 

[jack129]

Also I want to ask, if you have a working car 2006 E350 with PZEV fuel pump, would like to know how should the fuel pump sound like when you turn key fob to position 2 before turning ignition on. For me, when pin 3/5 jump on the A relay slots, i could heard a low humming sound on the fuel pump on driver side, and same low humming on passenger fuel pump side too, i don't hear buzzing or motor rotating. Not sure what's normal or what's not. If you can help confirm how the sound should be like, would very helpful.

Thanks!

 

[Kansascitysnuggle]

Hi everyone,
I have a 2006 E350 with PZEV fuel tank at about 138K mileages, still under the CA emission 15/150K warranty from MB. Car crank over but won't start, trying to trouble shoot if fuel pump has issue before tow over to dealer.
Right now, knows the following.
1. Checked fuse/relay in trunk, seems OK. Check starter relay in front under hood, seems OK, fuel line pressure is 0. Car will start for few seconds if spray some carb cleaner into the MAF.
2. Checked the voltage at the fuel pump behind driver side, no voltage, key fob turned to 2nd position.
3. Jumped the fuel pump relay on slot A on the rack (last/bottom one) (removed the relay, jumping pin 3 and 5 using wire), getting about 11.5V at the driver side fuel pump connector.
4. Checked the fuel pump relay on A (the other 2 pins of relay slot, forgot the number, 1? and 2?) this suppose to energize and create a charge to close pin 3 and 5 to deliver voltage to the pump, pin 1 and 2 together read 8V, not sure if 8V is correct? any one knows? Is the 8V suppose to be 12v? Pin 1 self give about 11.5v , and pin 2 is about 3V on itself.

So I would like to check why pin 1 and 2 on the relay slot only give 8V and it's not enough juice to close pin 3 and 5 or if this is normal. and where is this voltage coming from. Having a diagram / schematic would be helpful.
Please advise if you know what's my next time to check.

Thanks in advance!

It looks like a water leak from the back light into the circuit board. The rear SAM they call it. Good luck. I'm having the same problem. Under the fuse box.

 

[jack129]

Thanks for replying and tips.
Just update:
I got my E350 car started eventually after reading some others posts here about their cars won't start when fuel is below half tank. Out of idea/desperate, I filled up fuel high above 1/2 mark and then with a starting fluid was able to get car started, fuel pressure became normal at around 50 to 55psi after car started. It was strange that during cranking when fuel in tank was below 1/2, it was always at 0 pressure, never went above 0. At last didn't need the wiring diagram, but found a mitchell diagram website can get for a fee.

The fuel tank was somewhat defective according to the dealer after diagnosing and it's still under 150K miles warranty for PZEV car. Dealer replaced out the bad fuel tank, so far so good. 👍