P0192: Fuel rail pressure sensor signal reads too low
Fuel Rail Pressure Sensor Circuit Low
Severity: Inspect soon
GM service information can put the engine into reduced power when P0192 sets, and Saab service information notes possible loss of performance, so get it checked soon.
P0192 in short
P0192 means the fuel rail pressure sensor signal is lower than it should ever be, usually a wiring short, a poor connection or a failed sensor. On some 2014 Mazda3 models it instead flags a high-pressure pump that cannot build pressure. Expect possible reduced power. Get it checked soon.
The fuel rail pressure sensor tells the engine computer how much pressure is in the fuel rail. The computer feeds it a 5-volt reference and a ground, and the signal voltage rises as pressure rises.
P0192 sets when that signal stays below a low limit. Saab service information gives 0.20 V for more than 1 second as one example. That usually means the signal wire is shorted to ground, the sensor is faulty, or a connector pin is loose or corroded. GM treats it as a Type A code, and the driver may see "Reduced Engine Power".
Genuinely low pressure can also be the cause. Mazda says P0192 on the 2014 Mazda3 means the high-pressure pump is not reaching target pressure because of a manufacturing fault inside it. Volkswagen and GM have bulletins on diagnosing and replacing the sensor.
Most likely causes
Cause 1: Sensor wiring shorted to ground, or a loose or corroded connector
Common general cause- Why it ranks here
- Saab 9-3 service information lists harness breaks, shorts and oxidised or loose connector pins, and GM service information (Saab 9-4X) tests the reference, ground and signal circuits before blaming the sensor.
- What would change this
- Rises if the 5 V reference is low, the signal circuit is shorted to ground, or the connector is corroded. Falls if all circuits test good.
Cause 2: Fuel rail pressure sensor failed
Common general cause- Why it ranks here
- GM service information says to replace the sensor if the circuits test good. GM bulletins for 2014–2016 V8 trucks and SUVs replace the sensor when service information finds nothing, and Volkswagen has a bulletin on diagnosing the G247 sensor on 2009–2011 models.
- What would change this
- Rises if the circuits test good but the reading stays low. Falls if the signal jumps above 4.9 V when the shop jumps it to the reference, then reads normally with a known-good sensor.
Cause 3: High-pressure fuel pump not building pressure (2014 Mazda3)
Supported by vehicle data- Why it ranks here
- Mazda says P0192 on the 2014 Mazda3 is caused by the high-pressure pump not reaching target pressure because of a manufacturing error. Saab service information also lists genuinely low rail pressure.
- What would change this
- Rises on a 2014 Mazda3 when the dealer confirms the bulletin applies. Falls on other vehicles or if pressure is normal.
What to test first
Start at step 1. Each result tells you what it means and where to go next.
Step 1: Read all codes and freeze-frame data. Note whether P0087, P0191, P0193 or other 5-volt reference codes are stored too.
IfP0087 is stored too
It meansPressure may really be low. Check bulletins.
IfOnly P0192
It meansA circuit or sensor fault is more likely.
Step 2: Ask a dealer to check the VIN for fuel system bulletins.
IfIt is a 2014 Mazda3 covered by the bulletin
It meansMazda names the high-pressure pump.
Points to: High-pressure fuel pump not building pressure (2014 Mazda3)
IfNothing applies
It meansInspect the sensor connector.
Step 3: With the engine off and cool, look at the rail pressure sensor connector and harness for damage, corrosion or a loose plug.
IfThe plug is loose, corroded or the harness is damaged
It meansRepair it and clear the code.
Points to: Sensor wiring shorted to ground, or a loose or corroded connector
IfEverything looks good
It meansHave the circuits tested.
Step 4: Have a shop check the 5 V reference, ground and signal circuits at the sensor connector with a multimeter.
Warning:Do not unscrew the sensor from the fuel rail: the high-pressure side can hold pressure after shutdown and a fuel spray can cause injury or fire.
IfThe reference is outside 4.8–5.2 V or the signal wire is shorted to ground
It meansRepair the wiring.
Points to: Sensor wiring shorted to ground, or a loose or corroded connector
IfAll circuits test good
It meansReplace the sensor.
Symptoms
- Check engine light on
- "Reduced Engine Power" message or less power than usual
- Hard starting or rough running
Compare with: Check engine light with loss of power
How to fix
Step 1: With the engine off and cool, check that the rail pressure sensor connector is fully seated and not corroded.
Step 2: Ask a dealer to check the VIN for fuel system bulletins before buying a sensor or pump.
Parts and cost context
- Fuel rail pressure sensor:On many engines the sensor is part of the fuel rail or must be replaced with the system depressurised; that is shop work. Test the wiring first. Labour varies; get a quote.
Labor varies by vehicle and shop; get a quote before you approve a repair.
Compare used part prices on PartPriceGuideOn your vehicle
MazdaYour car
2014 · Mazda3
Supported by vehicle dataP0192 from a high-pressure fuel pump that does not build target pressure (manufacturing error). Bulletin status not verified.
01-010-14-2896BStatus unverified
Check engine light with P0191 or P0192
2012–2014mazda3, cx-5, mazda6 · issued · NHTSA 10098166
High-pressure pump does not build target pressure due to a manufacturing error; P0192 applies to the 2014 Mazda3.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
VolkswagenYour car
2009–2011 · Jetta
Supported by vehicle dataDiagnose the G247 rail pressure sensor carefully when P0192 sets, alone or with P0087 (also Passat, GTI, Golf, CC, Eos, Tiguan). Bulletin status not verified.
20-10-02Status unverified
MIL on, P0087 and/or P0192 stored
2009–2011jetta, passat, gti, cc, eos, tiguan · issued · NHTSA 10036494
Guidance to properly diagnose the fuel pressure sensor (G247).
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
ChevroletYour car
2014–2016 · Silverado 1500
Supported by vehicle dataIf service information finds nothing, GM replaces the rail pressure sensor (also Sierra, Tahoe, Suburban, Yukon, Escalade, Corvette). Bulletin status not verified.
PIP5279AStatus unverified
Service engine soon light with fuel pressure codes
2014–2016silverado-1500, tahoe, suburban, corvette · issued · NHTSA 10114645
If service information finds nothing, replace the rail pressure sensor.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
Related codes
P0192 questions
Is P0192 the sensor or the fuel pump?
Usually the sensor or its wiring. On the 2014 Mazda3, Mazda says it can mean the high-pressure pump is not building pressure, so check bulletins first.
Sources and review
- DTC P0192 or P0193 (LF1, LFW), 2011 Saab 9-4X service information
- P0192 00: fuel rail pressure sensor circuit low voltage/pressure, 2012 Saab 9-3 service information
- Service engine soon light with fuel pressure codes (bulletin PIP5279A)
- MIL on, P0087 and/or P0192 stored (bulletin 20-10-02)
- Check engine light with P0191 or P0192 (bulletin 01-010-14-2896B)
- Last reviewed
- Written by
- Saurabh K.
- Editorial review
- Pending
- Technician review
- Technician review pending
This page explains what a code usually means; it is not a substitute for a professional inspection. How we source and review · Report an error