The rail pressure sensor A measures the pressure in the high-pressure fuel rail of common-rail diesels and petrol 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) or a digital SENT sensor with two measuring channels. 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 petrol direct injection below 0.20 V for 5 s, GM diesel below 4.3 % of supply, GM 6.6 litre 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.
High severity. Can I keep driving?It is best to stop the car in a safe place and not continue your trip, because limp mode can severely limit power or stop the engine. If you only notice a lack of power, get off the highway as soon as possible.
Symptoms
- Check engine light on
- Limp mode or 'Reduced Engine Power'
- Hard starting, stalling
- Rough running
Most likely causes
- Signal wire shorted to ground, harness chafed
- 5 V reference open or shorted
- Connector corroded or loose
- Rail pressure sensor faulty internally
- Engine control module
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
- It can trigger limp mode.
- It affects emissions.
What each character of P0192 means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- 1: Air and fuel
- 92: Specific fault in that system
Frequently asked questions
Can I keep driving with code P0192?
It is best to stop the car in a safe place and not continue your trip, because limp mode can severely limit power or stop the engine. If you only notice a lack of power, get off the highway as soon as possible.
What causes code P0192?
The most common causes are: signal wire shorted to ground, harness chafed; 5 V reference open or shorted; connector corroded or loose.
Related codes
- P0190Fuel Rail Pressure Sensor A Circuit
- P0191Fuel Rail Pressure Sensor A Circuit Range/Performance
- P0193Fuel Rail Pressure Sensor A Circuit High
- P0194Fuel Rail Pressure Sensor A Circuit Intermittent/Erratic
- P01C0Fuel Rail Pressure Sensor Circuit Low Bank 2
- P06A6Sensor Reference Voltage A Circuit Range/Performance
Sources
- law.cornell.edu: 13 CCR 1968.2
- fordservicecontent.com: obd summary diesel 2023
- fordservicecontent.com: OBD Operations Summary Gasoline 2020 2023
- gsi.ext.gm.com: 18OBDG04 Engine Diagnostics
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.