Need help 06 5.9 4x4

[Jack Cross]

it's a new fca 10 minutes old but now days that don't mean anything I guess could be bad out of the box

 

[Jack Cross]

I can't figure out why there is 4.98 volts on the power and sigle wire of the rail sensor unless it's cause the pressure is high and making output read high.

 

[AH64ID]

I can't figure out why there is 4.98 volts on the power and sigle wire of the rail sensor unless it's cause the pressure is high and making output read high.

What are the volts with the engine off?

 

[Jack Cross]

What are the volts with the engine off?

I will double check tomorrow but I think the same I can't remember check it both ways.

 

[Ozymandias]

it's a new fca 10 minutes old but now days that don't mean anything I guess could be bad out of the box

That's what I'm talking about, it can be anything.

There is no sense changing random parts without knowing what's going on electronically.
It's also possible the ECM commands that Rail pressure.
You need to work with the workshop manual and a diagnostic computer and follow the troubleshooting tree.

And a voltmeter that is spot on the second digit behind the dot is very very rare and pricey, Fluke maybe if properly calibrated. Most I know and work with are only precise the first digit after the dot.

 

[Ozymandias]

https://mopar1973man.com/cummins/ar...3-fuel-pressure-sensor-voltage-too-high-r181/

 

[Ozymandias]

A try that costs nothing is re-torque the connector tube to 44lb/ft as this is often mentioned with your associate codes.

 

[AH64ID]

The CTS2 should be able to show commanded and actual rail pressure.

 

[Jack Cross]

The CTS2 should be able to show commanded and actual rail pressure.

25200 +/- 100or200 @idle

 

[AH64ID]

25200 +/- 100or200 @idle

Is that for both commanded and actual? Or just actual?

 

[Jack Cross]

fuel pressure with scanner shows asking for 6900psi and idling its at around 25200psi falls to around 20000 when warm.

Contribution test .
Do I need injectors?

 

[AH64ID]

That’s a CP3 issue, not an injector issue.

FCA is the most likely culprit, or FCA wiring. Does anything change when you unplug the FCA with the engine running?

 

[Jack Cross]

That’s a CP3 issue, not an injector issue.

FCA is the most likely culprit, or FCA wiring. Does anything change when you unplug the FCA with the engine running?

let me go check but I don't think it changes cause pump is wide open already.
fca is new but could be bad I guess.

 

[Jack Cross]

let me go check but I don't think it changes cause pump is wide open already.
fca is new but could be bad I guess.

It does not appear to change anything the pressure stays the same plugged in or not. I guess I need to trace wires back. any chance someone knows wich plug on the ecm it is and which wires/pin so I might can use meter to see if there's a break in the wires. that's gotta be it.
on cold start up pressure is around 25200 it drops when engine warms up but the injector supply line is pretty warm .
Thanks

 

[AH64ID]

Definitely look for a loose connection or an open, but that should also throw a code.

Can you try another FCA?

 

[Jack Cross]

Definitely look for a loose connection or an open, but that should also throw a code.

Can you try another FCA?

I have the one I took off but it is still doing the exact same thing with the new one as it was with the old one.

 

[BigPapa]

The connector pinouts are here:

https://www.turbodieselregister.com/threads/need-help-06-5-9-4x4.273236/page-3#post-2706955

https://www.turbodieselregister.com/threads/need-help-06-5-9-4x4.273236/page-3#post-2706956

 

[Jack Cross]

Definitely look for a loose connection or an open, but that should also throw a code.

Can you try another FCA?

I dohave codes but almost all of them say

The connector pinouts are here:

https://www.turbodieselregister.com/threads/need-help-06-5-9-4x4.273236/page-3#post-2706955

https://www.turbodieselregister.com/threads/need-help-06-5-9-4x4.273236/page-3#post-2706956

would the Fca Be number 19 ?

 

[Jack Cross]

sorry got side tracked.
I do have codes but almost all of them say lost communication with amplifier.

 

[Ozymandias]

Definitely measure the connection between FCA and ECM, this is well known to fail and some FCAs are even delivered with a pigtail because of this.

Do not only ohm them out, disconnect on both side and use a test light to give some load to the wire(s).