P0190 Code

[Paradox2018]

So I have a 2001 Mustang GT that has been throwing me the P0190 code on and off since I got the car a few weeks ago.

Sometimes the car will start perfectly fine and have no CEL, but other times the car will start and the rpms will be low. When this happens, the rpms usually raise back up and the car recovers and idles fine afterwards but about 25% of the time the car will barely start and die before completely turning on. The car will start right back up after this happens and runs fine afterwards.

I changed the fuel filter a few weeks ago and it seems to have slightly helped but the issue still occurs. I also replaced the FRPS a few days after the code first started happening.

Any ideas on what I can try next?

 

[wmburns]

Anytime a DTC with a "circuit malfunction" is called out it means there is something soooooooooooo wrong with the circuit that the PCM is unable to perform any real diagnostic. Think wiring, dirty connector, or totally failed sensor.

Since you have replaced the FRPS the focus should next be on the connector itself or a wring fault. Inspect the wiring harness looking for evidence of physical damage, rodent activity, or water damage.

Do you have an ODB2 scanner? If you did try monitoring the fuel pressure PID while performing a "wiggle test" up and down the wiring harness. Look for the PID to change (or drop out).

ForScan ODB2 scanner w ELM327 USB

ForScan ODB2 scanner w ELM327 USB

While working on your car have you ever wanted: to find an ODB2 operational PID value (say fuel pressure or MAF)? How about graph a PID value over time? Or compare multiple PID's over time? Access a bi-directional PCM control such as test a...

www.stangnet.com

>>From Ford service manual

P0190 - Fuel Rail Pressure Sensor Circuit Malfunction (FRP) VREF open in harness. VREF open in sensor. VREF open in PCM.

 

[Sluggie24]

Fuel pump is going bad

 

[Paradox2018]

Anytime a DTC with a "circuit malfunction" is called out it means there is something soooooooooooo wrong with the circuit that the PCM is unable to perform any real diagnostic. Think wiring, dirty connector, or totally failed sensor.

Since you have replaced the FRPS the focus should next be on the connector itself or a wring fault. Inspect the wiring harness looking for evidence of physical damage, rodent activity, or water damage.

Do you have an ODB2 scanner? If you did try monitoring the fuel pressure PID while performing a "wiggle test" up and down the wiring harness. Look for the PID to change (or drop out).

ForScan ODB2 scanner w ELM327 USB

ForScan ODB2 scanner w ELM327 USB

While working on your car have you ever wanted: to find an ODB2 operational PID value (say fuel pressure or MAF)? How about graph a PID value over time? Or compare multiple PID's over time? Access a bi-directional PCM control such as test a...

www.stangnet.com

>>From Ford service manual

P0190 - Fuel Rail Pressure Sensor Circuit Malfunction (FRP) ​ VREF open in harness. VREF open in sensor. VREF open in PCM.

I will check out the connector tomorrow morning. I do own an ODB2 scanner so I will monitor the fuel pressure tomorrow as well. Thank you for the suggestions, I will update this post when I figure anything out.