P0192 is a generic OBD-II powertrain fault code that means Fuel Rail Pressure Sensor "A" Circuit Low Input. The ECM/PCM has detected that the signal from the fuel rail pressure sensor is lower than the expected operating range.
P0192 can be encountered on vehicles from Mazda, Toyota, and Mitsubishi, among other manufacturers. The exact sensor design, wiring configuration, voltage specifications, fuel-system strategy, and diagnostic procedure can vary by engine and model year.
Fault Code Description
P0192 = Fuel Rail Pressure Sensor "A" Circuit Low Input.
Code type: Generic OBD-II Powertrain Code.
Likely fault location: Fuel rail pressure sensor "A", sensor signal circuit, wiring harness, electrical connector, sensor ground, reference-voltage circuit, or the fuel-pressure system.
The fuel rail pressure sensor provides the ECM/PCM with information about fuel pressure. When the sensor signal falls below the expected electrical range, the control module can store P0192.
The code does not automatically mean that the fuel rail pressure sensor itself is defective. A short to ground, damaged wiring, poor connector contact, incorrect reference voltage, sensor failure, or an actual fuel-pressure problem can contribute to the fault.
What Does P0192 Mean?
P0192 means that the engine computer has detected a low electrical input from the fuel rail pressure sensor "A" circuit.
The word Low refers primarily to the electrical sensor signal. It does not automatically mean that the fuel pressure itself is low.
For this reason, the sensor circuit should be tested before replacing the fuel rail pressure sensor.
Fuel Rail Pressure Sensor Location
The fuel rail pressure sensor is commonly installed on or near the fuel rail. The exact location depends on the engine and fuel-system design.
Some engines use a sensor mounted directly on the fuel rail, while other fuel systems use a different mounting arrangement.
Always confirm the exact sensor location and connector pinout using the vehicle-specific service information before testing or removing the component.
Symptoms of P0192
- Check Engine Light.
- Hard starting.
- Extended engine cranking.
- Engine hesitation.
- Poor acceleration.
- Reduced engine power.
- Rough or unstable idle.
- Engine stalling.
- Reduced fuel economy.
- Possible no-start condition in severe cases.
Common Causes of P0192
- Faulty fuel rail pressure sensor.
- Short to ground in the sensor signal circuit.
- Damaged sensor wiring.
- Corroded or loose electrical connector.
- Incorrect sensor reference voltage.
- Poor sensor ground.
- Open or damaged signal circuit.
- Water or fuel contamination at the connector.
- Actual low fuel pressure.
- Fuel pump problem.
- Restricted fuel filter or fuel supply.
- Fuel-pressure regulator problem.
- Rarely, an ECM/PCM fault.
How to Fix P0192
1. Scan the Vehicle
Use a professional scan tool to confirm P0192 and check for additional fuel-pressure, sensor, fuel-pump or injector-related codes.
Record the freeze-frame data before clearing the code. Engine RPM, load, temperature and fuel-pressure data can help determine the conditions under which P0192 was detected.
2. Check Fuel Rail Pressure Live Data
Monitor the fuel rail pressure sensor PID with the scan tool. Where supported, compare the actual or reported pressure with the commanded fuel pressure.
A sensor reading that remains unusually low, drops suddenly, or does not correspond with engine operating conditions should be investigated.
3. Inspect the Sensor Connector
Inspect the fuel rail pressure sensor connector for corrosion, loose terminals, damaged pins, water intrusion, fuel contamination or poor terminal tension.
4. Check Reference Voltage and Ground
Use the vehicle-specific wiring diagram to identify the sensor reference-voltage circuit, ground and signal circuit.
Verify that the reference voltage and sensor ground meet the manufacturer's specifications.
5. Check the Sensor Signal Circuit
Test the signal circuit for a short to ground, damaged wiring, excessive resistance or an intermittent connection.
A signal wire that is pulled abnormally low can cause P0192 even when the fuel rail pressure sensor itself is functioning correctly.
6. Check Actual Fuel Pressure
If the electrical circuit passes inspection, determine whether the actual fuel pressure is also below specification.
A genuine fuel-pressure problem can produce symptoms similar to a faulty sensor, so electrical testing and fuel-pressure testing should be considered together.
P0192 Diagnostic Signal Flow
P0192 OBD Live Data
OBD live data is an important part of diagnosing P0192. Monitor the fuel rail pressure sensor value while observing engine RPM, load and other available fuel-pressure parameters.
If the sensor reading remains extremely low while the engine is operating normally, check the sensor circuit, reference voltage and ground.
If the scan-tool value is low and actual fuel pressure is also low, investigate the fuel pump, fuel supply, filter, regulator and other fuel-system components.
P0192 Mazda
On applicable Mazda vehicles, P0192 indicates a low input from the fuel rail pressure sensor "A" circuit.
Diagnosis should include the fuel rail pressure sensor, connector, signal circuit, reference voltage, sensor ground and actual fuel pressure.
Because Mazda fuel-system designs vary between engines, always use the correct wiring diagram and pressure specifications for the exact vehicle.
P0192 Toyota
On applicable Toyota vehicles, P0192 indicates that the fuel rail pressure sensor signal is below the expected electrical range.
Check the sensor circuit for a short to ground, inspect the connector and wiring, verify reference voltage and ground, and compare the reported pressure with the actual fuel-system condition where applicable.
P0192 Mitsubishi
On applicable Mitsubishi vehicles, P0192 can be caused by a low fuel rail pressure sensor signal, wiring problems, poor electrical connections, incorrect reference voltage or an actual fuel-pressure problem.
The correct diagnosis should follow the Mitsubishi-specific wiring diagram, sensor specifications and fuel-pressure testing procedure.
P0192 vs P0191
P0191 indicates a fuel rail pressure sensor "A" range/performance problem, while P0192 specifically indicates a low input from the sensor circuit.
P0192 therefore places greater emphasis on the electrical signal being below the expected range, although an actual low-pressure condition should still be considered during diagnosis.
P0192 vs P0193
P0192 indicates a low input from the fuel rail pressure sensor "A" circuit, while P0193 indicates a high input.
The two codes should be diagnosed by checking the sensor signal, reference voltage, ground and wiring against the manufacturer's specifications.
Is P0192 Serious?
P0192 should not be ignored.
A low fuel-pressure sensor signal can affect fuel control and may cause hard starting, hesitation, poor acceleration, stalling or loss of engine power.
If the engine is running very poorly, repeatedly stalling, or experiencing severe power loss, the vehicle should be diagnosed before continued driving.
Can I Drive With P0192?
Limited driving may be possible if the engine is running normally and the Check Engine Light is steady. However, the problem should be diagnosed as soon as possible.
If there is severe hesitation, stalling, hard starting, major loss of power or evidence of an actual fuel-pressure problem, continued driving should be avoided.
P0192 Repair Cost
The repair cost depends on the actual cause of the fault.
- Electrical diagnosis: approximately $50–$150+.
- Wiring or connector repair: approximately $50–$300+.
- Fuel rail pressure sensor: approximately $100–$400+ depending on the vehicle.
- Fuel pump or fuel-pressure repair: approximately $200–$1,000+ depending on the vehicle.
- ECM/PCM repair: potentially considerably more.
These are general estimates only. Actual costs vary according to the vehicle, engine, parts prices, labor rate and failed component.
Common Repair Mistakes
Replacing the Sensor Immediately
Do not replace the fuel rail pressure sensor simply because P0192 is stored. A shorted signal wire, poor connector or incorrect reference voltage can produce the same code.
Assuming Low Signal Means Low Fuel Pressure
P0192 is an electrical low-input code. The sensor signal can be low even when actual fuel pressure is normal.
Ignoring the Sensor Ground
A poor sensor ground can alter the signal voltage and cause an incorrect low-input condition.
Using the Wrong Pinout
Fuel rail pressure sensor wiring differs between Mazda, Toyota, Mitsubishi and different engine generations. Always verify the connector pinout before applying test voltage.
Related Codes
- P0190 – Fuel Rail Pressure Sensor "A" Circuit
- P0191 – Fuel Rail Pressure Sensor "A" Circuit Range/Performance
- P0193 – Fuel Rail Pressure Sensor "A" Circuit High Input
- P0194 – Fuel Rail Pressure Sensor "A" Circuit Intermittent
- P0087 – Fuel Rail/System Pressure Too Low
- P0088 – Fuel Rail/System Pressure Too High
FAQ About P0192
What does P0192 mean?
P0192 means Fuel Rail Pressure Sensor "A" Circuit Low Input. The ECM/PCM has detected a sensor signal below the expected electrical range.
How do I fix P0192?
Start by checking the fuel rail pressure sensor, connector, wiring, reference voltage and ground. Then monitor OBD live data and determine whether actual fuel pressure is also low before replacing components.
What is the most common cause of P0192?
Possible causes include a faulty fuel rail pressure sensor, a short to ground in the signal circuit, damaged wiring, poor connector contact, incorrect reference voltage or an actual fuel-pressure problem.
Can a bad fuel rail pressure sensor cause P0192?
Yes. A defective sensor can produce a signal below the expected range. However, the wiring, reference voltage, ground and actual fuel pressure should also be checked.
Can low fuel pressure cause P0192?
Yes, an actual low-pressure condition can contribute to the fault depending on the vehicle's monitoring strategy. The electrical sensor signal should nevertheless be tested separately.
Where is the P0192 sensor located?
The fuel rail pressure sensor is commonly located on or near the fuel rail. The exact position depends on the engine and fuel-system design.
What does P0192 mean on Mazda?
On applicable Mazda vehicles, P0192 indicates a low input from the fuel rail pressure sensor "A" circuit. Diagnosis should include the sensor, wiring, connector, reference voltage, ground and actual fuel pressure.
What does P0192 mean on Toyota?
On applicable Toyota vehicles, P0192 indicates that the fuel rail pressure sensor signal is below the expected electrical range. The exact diagnostic procedure depends on the engine and fuel-system configuration.
What does P0192 mean on Mitsubishi?
On applicable Mitsubishi vehicles, P0192 indicates a low fuel rail pressure sensor input. Check the sensor circuit, wiring, connector, reference voltage, ground and actual fuel pressure.
What is the difference between P0191 and P0192?
P0191 indicates a fuel rail pressure sensor range/performance problem, while P0192 specifically indicates a low input from the sensor circuit.
What is the difference between P0192 and P0193?
P0192 indicates a low input, while P0193 indicates a high input from the fuel rail pressure sensor "A" circuit.
Final Result
P0192 is a generic OBD-II powertrain code meaning Fuel Rail Pressure Sensor "A" Circuit Low Input.
The most reliable diagnosis is to inspect the fuel rail pressure sensor, connector, signal wiring, reference voltage and ground, then compare OBD live data with the actual fuel-pressure condition before replacing parts.
On Mazda, Toyota and Mitsubishi vehicles, the exact sensor configuration, wiring, pressure specifications and diagnostic thresholds can vary by engine and model year. Always use the correct manufacturer service information for the final diagnosis.