Fuel Injector Group "B" Supply Voltage Circuit/Open
P2149 indicates an open or high-resistance circuit in the fuel injector group B electrical control circuit. The engine computer detected a malfunction in the ability to properly energize the fuel injectors in this group, preventing normal fuel delivery control.
What You Might Notice
- Engine misfire or rough idle
- Loss of power or hesitation during acceleration
- Check engine light illuminated
- Reduced fuel economy
- Difficulty starting the engine
Most Common Causes
- 1
Damaged fuel injector wiring or connector
Loose, corroded, or frayed wiring in the fuel injector group B circuit prevents proper electrical signal transmission. Check connectors for moisture, corrosion, or poor seating.
- 2
Faulty fuel injector
One or more fuel injectors in group B have failed electrically and cannot respond to control signals. Individual injector resistance testing can confirm which injector has failed.
- 3
Engine control module (ECM) malfunction
The ECM's fuel injector driver circuit or output stage has failed, preventing it from sending proper control signals to the injectors. This requires diagnostic testing of the ECM outputs.
- 4
Broken or disconnected wiring harness
An open circuit in the main harness supplying power or ground to the fuel injector group B circuit prevents current flow. Inspect the entire harness for breaks or disconnections.
How to Diagnose It
- 1
Check Damaged fuel injector wiring or connector — Loose, corroded, or frayed wiring in the fuel injector group B circuit prevents proper electrical signal transmission. Check connectors for moisture, corrosion, or poor seating.
- 2
Check Faulty fuel injector — One or more fuel injectors in group B have failed electrically and cannot respond to control signals. Individual injector resistance testing can confirm which injector has failed.
- 3
Check Engine control module (ECM) malfunction — The ECM's fuel injector driver circuit or output stage has failed, preventing it from sending proper control signals to the injectors. This requires diagnostic testing of the ECM outputs.
- 4
Check Broken or disconnected wiring harness — An open circuit in the main harness supplying power or ground to the fuel injector group B circuit prevents current flow. Inspect the entire harness for breaks or disconnections.
How to Fix It
- 1
Inspect and clean fuel injector connectors
Disconnect the fuel injector connectors for group B and inspect for corrosion, moisture, or poor contact. Clean with electrical contact cleaner and reconnect firmly. Test with the engine running.
- 2
Test and replace fuel injectors
Use a multimeter to test the resistance of each fuel injector in group B. Compare readings to manufacturer specifications. Replace any injectors with out-of-specification resistance values.
- 3
Repair or replace fuel injector wiring harness
Trace the entire fuel injector group B control circuit from the ECM to the injectors. Repair any broken, pinched, or corroded wires. Replace the harness section if damage is extensive.
- 4
Diagnose or replace engine control module
If all wiring and injectors test properly, the ECM injector driver output stage may be faulty. Have the ECM tested with specialized diagnostic equipment or replaced if confirmed defective.
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