Fuel Injector Group "B" Supply Voltage Circuit Low
P2150 indicates the engine control module detected low voltage in the Fuel Injector Group B control circuit. This means the injectors in that group are not receiving adequate electrical supply to function properly, affecting fuel delivery and engine performance.
What You Might Notice
- Check Engine Light illuminated
- Engine misfires or rough idle
- Reduced fuel economy
- Hesitation or lack of power during acceleration
- Difficulty starting the engine
Most Common Causes
- 1
Low battery voltage or weak alternator
Insufficient charging system output reduces voltage available to fuel injectors. Test battery voltage and alternator output to confirm adequate supply.
- 2
Corroded or loose injector connectors
Poor electrical connections at fuel injector Group B connectors create resistance and voltage drop. Inspect connectors for corrosion, damage, or loose pins.
- 3
Damaged fuel injector wiring harness
Breaks, cuts, or worn insulation in the wiring to Group B injectors cause voltage loss. Visually inspect all wiring for damage or pinch points.
- 4
Faulty fuel injector or injector driver module
A defective injector or the ECU's injector control circuit may fail to maintain proper voltage. Testing with a multimeter or scan tool can identify which component is failing.
How to Diagnose It
- 1
Check Low battery voltage or weak alternator — Insufficient charging system output reduces voltage available to fuel injectors. Test battery voltage and alternator output to confirm adequate supply.
- 2
Check Corroded or loose injector connectors — Poor electrical connections at fuel injector Group B connectors create resistance and voltage drop. Inspect connectors for corrosion, damage, or loose pins.
- 3
Check Damaged fuel injector wiring harness — Breaks, cuts, or worn insulation in the wiring to Group B injectors cause voltage loss. Visually inspect all wiring for damage or pinch points.
- 4
Check Faulty fuel injector or injector driver module — A defective injector or the ECU's injector control circuit may fail to maintain proper voltage. Testing with a multimeter or scan tool can identify which component is failing.
How to Fix It
- 1
Test and service charging system
Use a multimeter to verify battery voltage (12.6V+ at rest) and alternator output (13.5-14.5V running). Replace the alternator or battery if readings are low.
- 2
Inspect and clean fuel injector connectors
Disconnect and visually inspect all Group B fuel injector connectors for corrosion, bent pins, or debris. Clean with electrical contact cleaner and reconnect securely.
- 3
Repair or replace fuel injector wiring harness
Trace the wiring from the ECU to each Group B injector. Repair any damaged sections by splicing with proper connectors and heat shrink tubing, or replace the entire harness if extensively damaged.
- 4
Replace faulty fuel injector or driver module
Use a scan tool to perform injector balance testing. Replace any injector with significantly lower voltage or flow, or have the ECU tested and reprogrammed by a specialist if the driver circuit is faulty.
Need a deeper diagnosis?
Search for related repair guides or browse by system.