P0091 Fuel pressure regulator control circuit reading low (direct-injection fuel pump)

Fuel pressure regulator 1 control circuit low

P0091 in short

P0091 means the computer sees the control circuit for the fuel pressure regulator, on direct-injection cars the actuator on the high pressure fuel pump, reading low. Owners report the pump replaced, and one GM bulletin traces it to chafed wiring. It can cause reduced power, so have it checked soon.

On many direct-injection engines the computer controls fuel rail pressure through an actuator on the high pressure fuel pump. P0091 sets when the circuit that drives it reads low, for example from a short to ground.

Owner reports on 2020-2023 Traverse, 2016 Yukon XL and a Kia Optima mostly end with the high pressure pump replaced. A GM bulletin on the 2010 CTS instead ties P0091 to engine wiring chafing where the harness crosses the transmission bellhousing, so wiring is worth checking first.

Chrysler notes that on the 2006 PT Cruiser the code was being reported incorrectly for other circuit codes, so check the freeze-frame data and other stored codes.

Most likely causes

  1. High pressure fuel pump or its regulator actuator

    Supported by vehicle data
    Why it ranks here
    Owners on a 2020 and a 2023 Traverse report the high pressure pump replaced or faulty, and a Kia owner reports the regulator part named for P0091.
    What would change this
    Rises if rail pressure does not follow the commanded value or the pump actuator resistance is out of range. Falls if the pump and circuit test normal.
    How to test the fuel pump

  2. Chafed or damaged wiring to the actuator

    Supported by vehicle data
    Why it ranks here
    GM bulletin PI-0067 ties P0091 and reduced engine power on a 2010 CTS to chafing of the engine wiring over the transmission bellhousing.
    What would change this
    Rises if the harness shows rubbed insulation or a short to ground. Falls if the wiring tests good.

  3. Short or open in the actuator circuit or connector

    Common general cause
    Why it ranks here
    The Saab and GM service information has the actuator circuit checked for shorts, opens and the correct resistance, and describes the sibling code as setting when the circuit voltage is out of range.
    What would change this
    Rises if circuit checks show a fault. Falls if the circuit tests normal.

What to test first

Start at step 1. Each result tells you what it means and where to go next.

  1. Read all stored codes and freeze-frame data. Note whether P0090, P0089, P0088 or P0087 are stored with P0091.

    Low riskTool: OBD-II scan tool

    • IfP0090 stored too

      It meansBoth point to the pump actuator circuit.

      Go to step 2

    • IfP0091 alone or intermittent

      It meansCheck the wiring.

      Go to step 2

  2. Look at the engine wiring harness near the high pressure fuel pump and where it crosses the transmission bellhousing for rubbed insulation or a loose connector.

    Low risk

  3. Have the fuel rail pressure and the pump actuator circuit voltage, continuity and resistance tested.

    Best left to a shopTool: scan tool, multimeter, fuel pressure gauge

    Warning:Direct-injection fuel systems run at very high pressure. Leave this to a shop.

Symptoms

  • Check engine light
  • Reduced engine power message, clearing after the car sits Gets more serious: stop and have it checked.
  • Hard starting or hesitation

Compare with: Check engine light with loss of power

How to fix

  1. Ask a dealer whether your VIN has an open bulletin or warranty extension for the high pressure fuel pump.

Parts and cost context

  • Fuel pump:High pressure pumps are costly; test the circuit and wiring first. Labour varies; get a quote.

Labor varies by vehicle and shop; get a quote before you approve a repair.

Compare used part prices on PartPriceGuide

On your vehicle

Cadillac

  • 2010 · CTS

    Supported by vehicle data

    GM bulletin PI-0067 ties P0091 and a reduced engine power message to chafed engine wiring over the bellhousing.

  • PI-0067Status unverified

    MIL, reduced engine power, P0091 set

    2010cts · NHTSA 10034407

    Chafing of the engine wiring where the harness routes over the transmission bellhousing.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Chevrolet

  • 2020–2023 · Traverse

    Supported by vehicle data

    Owners report P0091 with the high pressure fuel pump replaced or internally faulty. Complaint signal only.

GMC

  • 2016 · Yukon XL

    Supported by vehicle data

    One owner reports reduced power mode with P0090 and P0091 that clears after the car sits. Complaint signal only.

Kia

  • 2013 · Optima

    Supported by vehicle data

    One owner reports P0091 pointing to the fuel pressure regulator while the dealer blamed the fuel pump. Complaint signal only.

  • P0090Fuel pressure regulator control circuit fault

    Same system Supported by vehicle data

    P0090 is the sibling code for the same actuator circuit; owners of a 2016 Yukon XL report both together.

  • P0089Fuel pressure regulator not holding the pressure the computer asks for

    Same system Possible — needs testing

    P0089 is the fuel pressure regulator performance code; Chrysler lists P0089 and P0091 together in bulletin 1801306.

All Fuel pump and injectors codes

P0091 questions

Is P0091 a bad fuel pump?

Often the high pressure pump on direct-injection engines, but wiring damage is also reported. Check the harness and circuit before replacing an expensive pump.

Sources and review

  1. DTC P0090, P0091 or P0092 (Saab 9-5 2010, 4-cyl petrol) — Saab / GM service information (read via saabwisonline.com mirror)
  2. NHTSA complaint ODI 1636540: 2016 GMC Yukon XL, P0090 and P0091 — NHTSA Office of Defects Investigation (owner complaint)
  3. NHTSA complaint ODI 2116254: 2020 Chevrolet Traverse, P0091 — NHTSA Office of Defects Investigation (owner complaint)
  4. NHTSA complaint ODI 2253985: 2023 Chevrolet Traverse, P0091 — NHTSA Office of Defects Investigation (owner complaint)
  5. NHTSA complaint ODI 1650931: 2013 Kia Optima, P0091 — NHTSA Office of Defects Investigation (owner complaint)
  6. GM PI-0067: MIL, reduced engine power, P0116-P0119, P00C9, P0091 (2010 CTS) — General Motors / NHTSA
  7. Chrysler bulletin 1801306: P2152, P0152, P0154, P0151, P0089, P0091, P0092 reported incorrectly (2006 PT Cruiser) — Stellantis (FCA) / NHTSA
Last reviewed
Written by
Saurabh K.
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