P2148 code meaning
Fuel Injector Group A Supply Voltage Circuit High
Powertrain system Generic code P21xx codes Check engine light
What P2148 means
P2148 flags group A's injector supply as too high. On GM's 2018 Duramax the high-side terminal of injector 1 or 4 shows 0.5 Ω or less to supply potential while the driver is off; same 5-of-10 counting at 100 ms, type A. Ford's 2023 diesels give it a different meaning: the chip that produces the boosted injector voltage inside the module reports an internal fault – a pointer to the control unit rather than the harness. GM's gasoline direct injection reads it as excess voltage on the high-side control line of cylinder 1. Bulletins show software and hardware causes: Hino's 2016 J08 trucks set P2148 and P2151 falsely until the ECU is reprogrammed (SB-15-023), and GM PIP6034 replaces the PCM on 2024–25 2.5 L LK0 models. The low fault is P2147.
P2148 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 P2148
- Check engine lamp on
- Misfire and rough running on the affected cylinders
- Often no drivability complaint when the cause is software
Common causes of P2148
- PossibleInjector supply wire shorted to battery voltage
- PossibleInternal fault of the injector boost circuit in the module
- PossibleSoftware falsely detecting the fault, reprogramming available
- Less likelyInjector of the group 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 P2148 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. |
| 48 | The exact fault in that area. |
What to do next
- Note P2148 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 P2148
What does P2148 mean?
P2148 means "Fuel Injector Group A Supply Voltage Circuit High". P2148 flags group A's injector supply as too high. It is a generic code, so it means the same on every make.
Is it safe to drive with P2148?
Drive gently and only to a workshop. With P2148 the car can go into limp mode (reduced power) to protect itself.
Will P2148 fail an emissions test?
Yes, it can. P2148 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 P2148 to fix?
Difficulty: hard. A typical repair takes 0.8 to 5 hours of work. This is a job for a workshop.
Will P2148 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.