Powertrain, generic · Fuel and air metering

P0193 Fuel Rail Pressure Sensor A Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

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. P0193 means the signal is above its valid range – typically an open sensor ground or a short to voltage; where the module uses a pull-up on the signal line (Saab/GM 2.0 diesel), an open signal wire also reads 5 V and sets P0193. Limits: Ford diesel above 3.17 V (its sensor stays well below that even at maximum pressure), Ford petrol direct injection above 4.80 V for 5 s, GM above about 95 % of supply, Saab above 4.7 V. Genuine overpressure is P0088 instead. On a fault the module uses a substitute value and usually limits power.

Likely causes

Sensor ground open or high-resistance
Signal wire open (with pull-up) or shorted to voltage
Connector corroded
Sensor faulty
Engine control module

Symptoms

  • Check engine light on
  • Limp mode or 'Reduced Engine Power'
  • Hard starting, stalling

Repair estimate

DifficultyMediumDIY possible
Parts and labour€50–500
Time0.5–2.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

fuel rail pressure sensorsensor wiringsensor reference voltage

Related codes

P0190P0191P0192P0194P01C1P0088

References: law.cornell.edu, fordservicecontent.com, fordservicecontent.com, gsi.ext.gm.com.