P2149 — Fuel Injector Group "B" Supply Voltage Circuit/Open

P2149 — Fuel Injector Group "B" Supply Voltage Circuit/Open. A fault in the fuel delivery and mixture control. Short, gentle driving to a shop is usually possible. Typical causes: faulty fuel rail pressure sensor or wiring, contaminated or incorrect fuel, clogged or leaking fuel injectors.

powertrain (engine/transmission)

Is it safe to drive?

Drive with caution Drive with caution. Mixture and fuel-pressure faults can cause stalling, hesitation in traffic and — when severe — catalyst damage. Avoid long trips until diagnosed.

How to diagnose with an OBD scanner

  1. Read the code and freeze frame Connect an OBD2 scanner, confirm P2149 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
  2. Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
  3. Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the fuel delivery and mixture control for damage, corrosion, chafing or poor contact.
  4. Subsystem check Measure fuel pressure at the rail and compare with factory specification at idle and under load.
  5. Subsystem check Check short-term and long-term fuel trims in live data to see which way the mixture is off.
  6. Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P2149 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for P2149 (parts and labor, USD, independent shop rates): Replace the fuel filter: $80–$200; Clean or replace injectors: $200–$800; Replace the pressure regulator or sensor: $150–$450; Replace the fuel pump: $400–$900. Overall, fixing P2149 usually costs between $80 and $900. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

What are the symptoms of P2149?

Drivers most often notice: rough idle and hesitation, loss of power under load, Check Engine Light on, fuel smell in severe cases.

What does OBD2 code P2149 mean?

P2149 — Fuel Injector Group "B" Supply Voltage Circuit/Open. A fault in the fuel delivery and mixture control. Short, gentle driving to a shop is usually possible. Typical causes: faulty fuel rail pressure sensor or wiring, contaminated or incorrect fuel, clogged or leaking fuel injectors.

What is the most common cause of P2149?

The most common causes are: faulty fuel rail pressure sensor or wiring, contaminated or incorrect fuel, clogged or leaking fuel injectors.

How much does it cost to fix P2149?

Replace the fuel filter — $80–$200; Clean or replace injectors — $200–$800; Replace the pressure regulator or sensor — $150–$450; Replace the fuel pump — $400–$900. Exact cost depends on the root cause, your vehicle and local labor rates — a proper diagnosis is the cheapest first step.

Will P2149 clear itself?

Sometimes P2149 clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

What does P2149 mean?

P2149 (Fuel Injector Group "B" Supply Voltage Circuit/Open) is stored when self-diagnostics detect abnormal readings or behaviour of the fuel delivery and mixture control. It belongs to the powertrain (engine/transmission) category.

This code does not appear from a single bad reading: the module must see the fault condition repeat under defined operating conditions before it turns on the warning light. The freeze frame captured with P2149 — engine load, rpm, temperature, speed — tells you exactly when the problem occurs, so reproduce those conditions when testing.

Common symptoms of P2149

  • rough idle and hesitation
  • loss of power under load
  • Check Engine Light on
  • fuel smell in severe cases
  • hard starting or long cranking

What causes P2149?

  • faulty fuel pressure regulator
  • vacuum or intake leaks skewing the mixture
  • faulty fuel rail pressure sensor or wiring
  • clogged or leaking fuel injectors
  • weak fuel pump or clogged fuel filter
  • contaminated or incorrect fuel

How to diagnose P2149

  1. Connect an OBD2 scanner, confirm P2149 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
  2. Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
  3. Visually inspect the wiring harness and connectors related to the fuel delivery and mixture control for damage, corrosion, chafing or poor contact.
  4. Measure fuel pressure at the rail and compare with factory specification at idle and under load.
  5. Check short-term and long-term fuel trims in live data to see which way the mixture is off.
  6. Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P2149 does not return.

How to fix P2149

Start with the cheapest and most common causes before replacing expensive parts:

  • Replace the fuel filter — $80–$200
  • Clean or replace injectors — $200–$800
  • Replace the pressure regulator or sensor — $150–$450
  • Replace the fuel pump — $400–$900

How much does it cost to fix P2149?

Repair cost depends on which component actually failed. Typical scenarios for P2149 (parts and labor, USD, independent shop rates):

  • Replace the fuel filter: $80–$200
  • Clean or replace injectors: $200–$800
  • Replace the pressure regulator or sensor: $150–$450
  • Replace the fuel pump: $400–$900

Overall, fixing P2149 usually costs between $80 and $900. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Can you drive with P2149?

Drive with caution. Mixture and fuel-pressure faults can cause stalling, hesitation in traffic and — when severe — catalyst damage. Avoid long trips until diagnosed.

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