What P0192 means
The rail pressure sensor A measures the pressure in the high-pressure fuel rail of common-rail diesels and gasoline direct-injection engines; it is either a three-wire sensor (5 V reference, ground, signal rising with pressure, about 0.5 V at 0 bar (0.0 psi)) or a digital SENT sensor with two measuring channels.
How the engine computer detects it
The engine module uses it as the feedback signal for rail pressure control. P0192 means the signal is below the physically possible range – typically a signal wire shorted to ground or an open 5 V reference. Limits: Ford diesel below 0.13 V for 0.5 s, Ford gasoline direct injection below 0.20 V for 5 s, GM diesel below 4.3 % of supply, GM 6.6 liter below 0.19 V, Saab/GM 2.0 diesel below 0.25 V. Monitored continuously; GM one trip, Saab two. If several sensors report low voltage at once, the shared 5 V reference is the likely cause. On a fault the module uses a substitute value and usually limits power.
Written from public technical sources and not yet checked by a mechanic. How we write these pages
Symptoms
- Check engine light on
- Limp mode or 'Reduced Engine Power'
- Hard starting, stalling
- Rough running
Common causes
- Signal wire shorted to ground, harness chafed Most likely
- 5 V reference open or shorted Possible
- Connector corroded or loose Possible
- Rail pressure sensor faulty internally Possible
- Engine control module Less likely
How to diagnose P0192
- Read every stored code with an OBD-II scanner. If misfire or fuel trim codes are there too, fix those first: they often cause this one.
- Inspect the parts involved: fuel rail pressure sensor, sensor wiring, sensor reference voltage.
- Work through the causes above from most to least likely, cheapest checks first.
- Clear the code and drive a full drive cycle to confirm the repair held.
Vehicles that report P0192 most
| Vehicle | Years | Reports | Share | Median miles |
|---|---|---|---|---|
| Mazda CX-5 | 2015–2019 | 9 | — |
Counts of owner complaints to the NHTSA that mention P0192 (15 in total), not failure rates: popular models get more complaints simply because more of them are on the road. Models with fewer than 3 complaints are left out.
Reading the code
- P
- Powertrain
- 0
- Generic (SAE) code
- 1
- Fuel and air metering
- 92
- Specific fault
Questions drivers ask
Can I drive with code P0192?
Drive gently and only as far as you need to. The engine computer may limit power to protect the engine, so avoid highways and heavy traffic until it's fixed. If the check engine light starts flashing, pull over.
Will my car pass an emissions inspection with P0192?
Probably not in states that test vehicles with an OBD-II scan: an emissions-related code that keeps the check engine light on is usually an automatic fail. Rules differ by state and county, so check yours.
Can I fix P0192 myself?
Often yes, with an OBD-II scanner and basic tools. Difficulty: medium. Start with the cheapest checks before replacing expensive parts.
This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.