P2150 — Fuel Injector Group "B" Supply Voltage Circuit Low

OBD2 code P2150 flags a problem with the fuel delivery and mixture control (fuel injector group "B" supply voltage circuit low). Short, gentle driving to a shop is usually possible. Common culprits: faulty fuel pressure regulator, faulty fuel rail pressure sensor or wiring, vacuum or intake leaks skewing the mixture.

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

Read the code and freeze frame Connect an OBD2 scanner, confirm P2150 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
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.
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.
Subsystem check Check for supply voltage at the fuel injector group "B" supply voltage connector first; then measure resistance from the signal wire to ground — near-zero ohms confirms a short to ground in the harness.
Subsystem check Measure fuel pressure at the rail and compare with factory specification at idle and under load.
Subsystem check Check short-term and long-term fuel trims in live data to see which way the mixture is off.
Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P2150 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for P2150 (parts and labor, USD, independent shop rates): Replace the fuel filter: $80–$200; Clean or replace injectors: $200–$800; Replace the fuel pump: $400–$900; Replace the pressure regulator or sensor: $150–$450. Overall, fixing P2150 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

Is it safe to drive with P2150?

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 do I diagnose P2150 myself?

Start with a scan: confirm P2150, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the fuel injector group "B" supply voltage, and verify the suspect component against live data before buying parts.

Will P2150 clear itself?

Sometimes P2150 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 are the symptoms of P2150?

Drivers most often notice: hard starting or long cranking, loss of power under load, rough idle and hesitation, fuel smell in severe cases.

What is the most common cause of P2150?

The most common causes are: faulty fuel pressure regulator, faulty fuel rail pressure sensor or wiring, vacuum or intake leaks skewing the mixture.

What does P2150 mean?

When P2150 appears on a scan, it means the control module has flagged a problem in the fuel delivery and mixture control: fuel injector group "B" supply voltage circuit low. The fault sits in the powertrain (engine/transmission) group of the OBD2 standard.

“Circuit low” means the voltage on the fuel injector group "B" supply voltage circuit stays below the expected minimum — close to ground. The usual physical reasons are a short to ground, a chafed wire touching metal, a missing supply voltage, or a failed component dragging the signal down.

To set P2150, the control module compares live readings of the fuel delivery and mixture control against calibrated limits, usually over several drive cycles. Alongside the code it stores a freeze frame — a snapshot of rpm, load, coolant temperature and vehicle speed at the moment of failure. Reading that snapshot first saves diagnostic time.

What causes P2150?

failed fuel injector group "B" supply voltage pulling the signal low
signal wire shorted to ground (chafed insulation)
missing supply voltage to the fuel injector group "B" supply voltage
contaminated or incorrect fuel
faulty fuel rail pressure sensor or wiring
faulty fuel pressure regulator
vacuum or intake leaks skewing the mixture
weak fuel pump or clogged fuel filter
clogged or leaking fuel injectors

Common symptoms of P2150

hard starting or long cranking
loss of power under load
rough idle and hesitation
fuel smell in severe cases
increased fuel consumption

How to diagnose P2150

Connect an OBD2 scanner, confirm P2150 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
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.
Visually inspect the wiring harness and connectors related to the fuel delivery and mixture control for damage, corrosion, chafing or poor contact.
Check for supply voltage at the fuel injector group "B" supply voltage connector first; then measure resistance from the signal wire to ground — near-zero ohms confirms a short to ground in the harness.
Measure fuel pressure at the rail and compare with factory specification at idle and under load.
Check short-term and long-term fuel trims in live data to see which way the mixture is off.
Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P2150 does not return.

How to fix P2150

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 fuel pump — $400–$900
Replace the pressure regulator or sensor — $150–$450

How much does it cost to fix P2150?

Repair cost depends on which component actually failed. Typical scenarios for P2150 (parts and labor, USD, independent shop rates):

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

Overall, fixing P2150 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 P2150?