Fuel Injector Group "C" Supply Voltage Circuit High
P2154 indicates the fuel injector group C circuit is receiving excessive voltage, preventing proper fuel injection control. This occurs when the PCM detects a voltage signal higher than the expected operating range for the injector control circuit, disrupting precise fuel delivery timing and atomization.
What You Might Notice
- Check Engine Light illuminated
- Rough idle or engine misfire
- Reduced fuel economy
- Difficulty starting the engine
- Lack of power during acceleration
Most Common Causes
- 1
Damaged fuel injector wiring or connector
Frayed, corroded, or damaged wiring in the injector circuit can cause high voltage readings. Check connectors for corrosion, moisture, or loose connections on injector group C.
- 2
Faulty fuel injector driver module
The injector driver circuit in the PCM or a separate control module may be malfunctioning, sending excessive voltage to the injectors. This typically requires module testing or replacement.
- 3
High resistance in injector coil
A fuel injector with internal resistance issues or a short circuit can cause abnormal voltage readings in the group C circuit. Individual injectors may need testing and replacement.
- 4
ECU/PCM electrical fault
Internal PCM voltage regulation failure or a ground circuit problem can produce high voltage signals to the entire injector group. Requires professional ECU diagnostics.
How to Diagnose It
- 1
Check Damaged fuel injector wiring or connector — Frayed, corroded, or damaged wiring in the injector circuit can cause high voltage readings. Check connectors for corrosion, moisture, or loose connections on injector group C.
- 2
Check Faulty fuel injector driver module — The injector driver circuit in the PCM or a separate control module may be malfunctioning, sending excessive voltage to the injectors. This typically requires module testing or replacement.
- 3
Check High resistance in injector coil — A fuel injector with internal resistance issues or a short circuit can cause abnormal voltage readings in the group C circuit. Individual injectors may need testing and replacement.
- 4
Check ECU/PCM electrical fault — Internal PCM voltage regulation failure or a ground circuit problem can produce high voltage signals to the entire injector group. Requires professional ECU diagnostics.
How to Fix It
- 1
Inspect and clean injector connectors
Remove and inspect all fuel injector connectors in group C for corrosion, moisture, or loose pins. Clean with electrical contact cleaner and reseat firmly. Check wiring for damage or exposed conductors.
- 2
Test individual fuel injectors
Use a fuel injector tester to measure ohm resistance and spray pattern of each injector in group C. Replace any injector with out-of-spec resistance or poor atomization pattern.
- 3
Repair or replace injector wiring harness
Inspect the complete wiring harness from injectors to PCM for shorts, breaks, or poor grounds. Repair damaged sections with proper automotive-grade wiring and connectors, or replace entire harness if severely compromised.
- 4
Diagnose and repair PCM/injector driver circuit
If wiring and injectors test normal, have the PCM or external injector driver module professionally tested for voltage regulation faults. May require module reprogramming or replacement by a qualified technician.
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