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Hello everyone, I have read through the forums and really can't find what i'm looking for and I am hoping you can help. So here recently I had troubles with my car getting a p0190 code, i ended up replacing my fuel filter, fuel pump, some fuel module that is after the ccrm I believe. Finally everything works great, about 4 weeks later, as i am on my way home to my moms house, i stopped at a gas station close to my her house and my car started funny. checked and it ran the same code. I am so confused and i don't really know what to do, any help would be appreciated. Thank you for your help. Oh also, I just had an x pipe put in and i have a slight exhaust leak. Again thanks!
 

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Discussion Starter #3
I haven't done very many mods, basic exhaust, x pipe, throttle body, which was years ago, and a cai. I looked for leaks and couldn't find any. Honestly I love working on my car but I am still learning and i don't know really how to check for the other things
 

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Bad fuel rail pressure sensor (FRPS).
 

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Here is a link the the Ford shop manual's description of P0190, the generic description linked to above will send you off in a bunch of wrong directions:

P0190 indicates the reference voltage (Vref) from the PCM to the FRPS is not between 4 to 6 V as it should be. This could be a wiring problem (a broken wire between the PCM and FRPS), a bad FRPS, or a bad PCM. The FRPS, Throttle Position Sensor (TPS) and Differential Feedback Pressure EGR (DPFE) sensor share the same PCM Vref--if either of them were defective it could cause P0190.

So:

  • Check the voltage between the brown/white wire at the FRPS and ground, key on engine off (KOEO). It should be 4 to 6 V with around 5 V being "normal";

  • If it is not in that range unplug the TPS and check again at the FRPS, if the reference voltage is now present the TPS may be shorted internally);

  • If there is still no reference voltage at the FRPS unplug the DFPE sensor and check again at the FRPS, if the reference voltage is now present the DFPE sensor may be shorted internally);
If unplugging the TPS and DFPE sensor does not restore Vref on the brown/white wire at the FRPS then the wiring harness is open someplace between the PCM and the FRPS, or the PCMs internal Vref supply is bad.
 

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Here is a link the the Ford shop manual's description of P0190, the generic description linked to above will send you off in a bunch of wrong directions:

P0190 indicates the reference voltage (Vref) from the PCM to the FRPS is not between 4 to 6 V as it should be. This could be a wiring problem (a broken wire between the PCM and FRPS), a bad FRPS, or a bad PCM. The FRPS, Throttle Position Sensor (TPS) and Differential Feedback Pressure EGR (DPFE) sensor share the same PCM Vref--if either of them were defective it could cause P0190.

So:

  • Check the voltage between the brown/white wire at the FRPS and ground, key on engine off (KOEO). It should be 4 to 6 V with around 5 V being "normal";

  • If it is not in that range unplug the TPS and check again at the FRPS, if the reference voltage is now present the TPS may be shorted internally);

  • If there is still no reference voltage at the FRPS unplug the DFPE sensor and check again at the FRPS, if the reference voltage is now present the DFPE sensor may be shorted internally);
If unplugging the TPS and DFPE sensor does not restore Vref on the brown/white wire at the FRPS then the wiring harness is open someplace between the PCM and the FRPS, or the PCMs internal Vref supply is bad.
Rep, good information here! Hope you find the problem OP.
 
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