P0191

Medium Severity

Fuel Rail Pressure Sensor Circuit Range/Performance

Fuel System

What Does P0191 Mean?

The fuel rail pressure sensor reading does not match expected values. Usually a sensor fault or wiring issue.

Common Fix

Replace fuel rail pressure sensor

Estimated Cost (DIY)

$30 - $80

Symptoms

  • ⚠️Engine performance issues
  • ⚠️Hard starting
  • ⚠️Stalling
  • ⚠️Check engine light

Related Symptoms

Check engine light on

Common Causes

Faulty fuel rail pressure sensorlikely
Wiring issuepossible
Actual fuel pressure problempossible

How to Diagnose P0191

  1. 1Check sensor wiring
  2. 2Compare sensor reading to mechanical gauge
  3. 3Test fuel pump pressure
  4. 4Replace sensor if readings incorrect

OEM Diagnostic Flowchart

Scroll to load technician if/then branches.

Read live data and freeze frame for P0191 to pinpoint the cause before buying parts.

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Related Resources

Repair guides, symptom pages, and wiring diagrams related to P0191.

OEM Manual Evidence

Browse →
2013 GMC Truck Terrain AWD V6-3.6L A L L Diagnostic Trouble Codes ( DTC )OEM Manual

A L L Diagnostic Trouble Codes ( DTC ) — 2013 GMC Truck Terrain AWD V6-3.6L Service Manual | Operation CHARM Operation CHARM : Car repair m...

2013 GMC Truck Terrain FWD V6-3.6L A L L Diagnostic Trouble Codes ( DTC )OEM Manual

A L L Diagnostic Trouble Codes ( DTC ) — 2013 GMC Truck Terrain FWD V6-3.6L Service Manual | Operation CHARM Operation CHARM : Car repair m...

2013 GMC Truck Acadia FWD V6-3.6L A L L Diagnostic Trouble Codes ( DTC )OEM Manual

A L L Diagnostic Trouble Codes ( DTC ) — 2013 GMC Truck Acadia FWD V6-3.6L Service Manual | Operation CHARM Operation CHARM : Car repair ma...

2013 GMC Truck Acadia AWD V6-3.6L A L L Diagnostic Trouble Codes ( DTC )OEM Manual

A L L Diagnostic Trouble Codes ( DTC ) — 2013 GMC Truck Acadia AWD V6-3.6L Service Manual | Operation CHARM Operation CHARM : Car repair ma...

Related Symptoms

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Check engine light onSymptom Hub

A check-engine light is a graph entry point into code pages, symptom-specific diagnosis, and the exact repair categories most often associated with those failures.

Exact Vehicle Hubs

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2013 Gmc Truck Acadia Awd V6 3.6l Repair HubManual

Open the exact vehicle hub grounded by OEM manual evidence related to P0191.

2013 Gmc Truck Acadia Fwd V6 3.6l Repair HubManual

Open the exact vehicle hub grounded by OEM manual evidence related to P0191.

2013 Gmc Truck Terrain Awd V6 3.6l Repair HubManual

Open the exact vehicle hub grounded by OEM manual evidence related to P0191.

2013 Gmc Truck Terrain Fwd V6 3.6l Repair HubManual

Open the exact vehicle hub grounded by OEM manual evidence related to P0191.

Related Codes

P0192: Fuel Rail Pressure Sensor Circuit LowRelated

Fuel rail pressure sensor reads too low. Could be a sensor fault or actually low fuel pressure.

P0193: Fuel Rail Pressure Sensor Circuit HighRelated

Fuel rail pressure sensor reads higher than expected.

P0171: System Too Lean (Bank 1)Related

The engine is running lean on bank 1 — too much air or not enough fuel. The ECM has maxed out its fuel trim trying to compensate. Common causes include vacuum leaks and dirty MAF sensors.

Frequently Asked Questions

What does the fuel rail pressure sensor do?
It monitors fuel pressure in the fuel rail so the ECM can adjust injector pulse width for proper fuel delivery.
Is this sensor easy to replace?
Usually yes — it screws into the fuel rail. Relieve fuel pressure first and have a rag ready for fuel spillage.

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