P2149: Fuel Injector Group B Supply Voltage Circuit/Open

What does P2149 mean?

P2149 is the open or general fault of the second shared injector supply. Group membership depends on the engine: GM's 2009 Duramax places injectors 7 and 6 in group 2 (6 ms, type A), whereas GM's 2018 tables pair injectors 2 and 5 in the V8 – so the cylinders must be looked up for each engine. VW's 2014 TSI and VR6 engines use the same current window as for group A, under 2.6 A or above about 14.7–14.9 A. GM petrol direct injection treats P2149 as the high-side control line of cylinder 2: on the 2023–24 Corvette LT6 bulletin 24-NA-106 traces it, with rail pressure codes, to water entering a wrong 12-way connector on bank 2. A Mercedes M254 bulletin lists P2149 among faults caused by fuel boiling in the low-pressure system.

The code tells you which monitor failed, not which part is broken. Test before replacing parts.

Symptoms

• Misfire on the cylinders of group B
• Rough running and reduced power
• Check engine lamp on

Common causes

• High Injector harness damaged or wire open
• Medium Water entering an injector harness connector
• Medium Open coil or piezo stack in an injector of the group
• Low Low rail pressure from fuel vapour triggering follow-up faults

Likelihood is a general estimate across vehicles; your make and model may differ.