HomeTrouble CodesP2148

P2148 — Fuel Injector Group Supply Voltage Circuit High

Manufacturer-specificPowertrain (engine & transmission)

P2148 signals that the voltage supplied to the fuel injector group control circuit is higher than the expected range. The PCM detects an over‑voltage condition in the circuit that powers the injectors.

Symptoms

What causes it — most likely first

1. Faulty injector driver module

The driver module that switches power to the injector group can develop an internal fault, causing it to output excessive voltage.

2. Short to higher voltage in wiring

A wire in the injector supply circuit may be shorted to a 12‑volt source or to a voltage‑boost circuit, raising the measured voltage.

3. Corroded or loose connector

Poor contact at the injector harness can cause the circuit to reference a different voltage reference, leading to a high reading.

4. Bad ground or reference voltage

An inadequate ground or fluctuating reference voltage can make the control circuit appear over‑voltage.

5. PCM output circuit failure

A failure inside the PCM's injector driver output stage can produce excess voltage, but this is rare.

How it's diagnosed

  1. Inspect the injector harness and connectors for damage, corrosion, or loose pins.
  2. Measure the supply voltage at the injector driver module with the key on, engine off to verify it is within specifications.
  3. Check for shorts to power in the wiring harness using a multimeter or ohmmeter.
  4. Test the operation of the injector driver module by swapping it with a known good unit or performing a resistance test.
  5. Verify ground connections and continuity to the chassis.

Code facts & related codes

SystemPowertrain (engine & transmission)
StandardizationManufacturer-specific (P1/B1/C1/U1)

Frequently asked

Will replacing the PCM fix P2148?

Usually not. The PCM's output circuit rarely fails; most often the issue is a wiring fault, connector problem, or a defective injector driver module.

Can a bad injector cause this code?

A shorted injector can pull excessive current but does not typically raise the supply voltage; the code is related to the control circuit voltage, not the injector itself.

Is the code urgent?

Yes. An over‑voltage condition can damage the injector driver module or other components, so the issue should be diagnosed and repaired promptly.

Do I need to replace all injectors when this code appears?

No. Only the affected injector group circuit components need attention; replacing injectors unnecessarily is not required.