Low side fuel pressure P018C

[silver2k]

Hi,

I am having a rough idle and occasional stalling at idle on my 2013 SHO. Plugs/boots are newish (<10k miles)

I have replaced the tank fuel pump, high pressure fuel pump and fuel pump driver module. When I hook up to FORSCAN it shows a code of P018C and low side pressure low. Looking into the data it's getting no reading from the low side fuel pressure sensor (~0V not sure if this is a pull down sensor)

I can't seem to find what this sensor is? If you look at the screenshot, the fuel rail high pressure sensor is working as expected. This is not the same sensor as 528kPa is way too low and the fuel rail sensor is only plumbed in after the high pressure fuel pump.

I did a lot of searching and found some references to a low pressure fuel sensor for the 3.5L ecoboost F-150s but none for our cars. Looking for a replacement item, I only see the fuel rail high pressure sensor.

As a comparison, I hooked FORSCAN up to my wife's 2016 3.5 ecoboost explorer sport, and her low fuel pressure sensor showed live data.

Even looking in the Ford 2013 service manual, hasn't given me much. Any thoughts on what part is or the location of this?

 

[Texas Marauder]

Looks like it is near the fuel tank. Can't confirm, only info I found.

 

[Yirmiyahu]

Any conclusion? I'm experiencing similar symptoms, however my car has not ever stalled. Trying to figure out why my dw300 is not matching commanded fuel pressure, so if this sensor fixed your issue I'm very interested to know.

 

[bob86z]

Any conclusion? I'm experiencing similar symptoms, however my car has not ever stalled. Trying to figure out why my dw300 is not matching commanded fuel pressure, so if this sensor fixed your issue I'm very interested to know.

My car is doing the same thing. I have a dw300 in the tank, a xdi hpfp, and I even changed the driver module. And still nothing

 

[kryptto]

Short version: that code points to the low-side fuel pressure sensor circuit on your 3.5L EcoBoost—not the rail (high-pressure) side. “P018C – Fuel Pressure Sensor B Circuit Low” means the PCM is seeing the sensor’s signal voltage too low (typically near 0 V), which is usually an electrical issue rather than a purely mechanical fuel problem.

Most likely causes (in order)

Connector/harness fault at the low-pressure fuel sensor (3-wire transducer on the feed line near the HPFP):

Loose/broken lock tab, pushed-out pin, corrosion, oil intrusion
Wire chafe/short to ground in the first 12–18" of loom
Failed sensor (internal short pulls signal low)
5 V reference or sensor ground problem shared with other sensors
If you had other 5 V sensor DTCs (MAP, APP, etc.), suspect a ref-line issue
Fuel Pump Driver Module/ground issue (less common for this code, but can disturb the low-side reading intermittently)

Actual low feed pressure from the in-tank pump or clogged filter can contribute, but the “circuit low” wording and your “intermittent/maturing” status point first to wiring/sensor.

Scan live data (FORScan PIDs): Look for low-side fuel pressure (often ~380–550 kPa / ~55–80 psi at idle). If it’s stuck near 0 kPa KOEO/idle, that’s a classic circuit-low symptom.