P2151 code meaning
Fuel Injector Group B Supply Voltage Circuit High
Powertrain system Generic code P21xx codes Check engine light
What P2151 means
P2151 marks the group B injector supply as too high. GM's 2018 Duramax checks the high-side pins of the bank 2 injectors with the driver switched off and sets the code at 0.5 Ω or less to supply potential, 5 of 10 samples, type A. On Ford's 2023 diesels the same number stands for an internal fault reported by the boost voltage chip of the module, so a harness check alone rarely solves it. GM gasoline direct injection uses it for excess voltage on the high-side control line of cylinder 2. Bulletins point mostly to the control unit: Hino's 2016 J08 engines set P2148 and P2151 falsely and need new ECU software (SB-15-023), and GM PIP6034 replaces the PCM of 2024–25 Traverse, Acadia and Enclave with the 2.5 L LK0. P2150 is the low counterpart.
P2151 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyHard
- Typical labor0.8 to 5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2151
- Check engine lamp on
- Misfire on the group B cylinders
- Sometimes no noticeable symptom besides the lamp
Common causes of P2151
- PossibleInternal fault of the injector boost circuit in the module
- PossibleSoftware falsely detecting the fault, reprogramming available
- PossibleGroup B supply wire shorted to battery voltage
- Less likelyInjector of group B with internal short
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Fuel injectorInjector wiringEngine control module
What each part of P2151 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 1 | Area: fuel and air metering. |
| 51 | The exact fault in that area. |
What to do next
- Note P2151 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2151
What does P2151 mean?
P2151 means "Fuel Injector Group B Supply Voltage Circuit High". P2151 marks the group B injector supply as too high. It is a generic code, so it means the same on every make.
Is it safe to drive with P2151?
Drive gently and only to a workshop. With P2151 the car can go into limp mode (reduced power) to protect itself.
Will P2151 fail an emissions test?
Yes, it can. P2151 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2151 to fix?
Difficulty: hard. A typical repair takes 0.8 to 5 hours of work. This is a job for a workshop.
Will P2151 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.