P0174 — Fuel System Too Lean Bank 2
What it means: Fuel System Too Lean Bank 2.
How serious / can you keep driving: Serious. Power derate likely — plan to stop soon.
Check first: Smoke-test intake system
Don't risk it — look up listed providers near you and give them this code when you call.
Listed providers nearest Indianapolis, IN
Closest first. Tell them P0174 and what the truck is doing. RoadService.app lists these providers and does not employ them or carry out the repair.
- 0.0 mi away — based in Indianapolis, IN · (317) 789-5002
- 0.0 mi away — based in Indianapolis, IN · (317) 300-7000
- 0.0 mi away — based in Indianapolis, IN · (317) 646-8208
Seen on: Heavy Truck/Diesel
What P0174 means
Fuel System Too Lean Bank 2. Common causes: Vacuum leak downstream.
How serious is it?
Serious. Power derate likely — plan to stop soon.
Most likely causes
- Vacuum leak downstream
- Clogged injectors
- weak fuel pump
First moves (roadside)
- Smoke-test intake system
- check fuel pump output pressure
FAQ
Fuel System Too Lean Bank 2. Common causes: Vacuum leak downstream.
Serious — Power derate likely — plan to stop soon.
The most common cause is: Vacuum leak downstream. Other possibilities include Clogged injectors; weak fuel pump.
Power derate likely — plan to stop soon. When in doubt, get a qualified mobile diesel tech on the truck before continuing.
Related codes
Codes that commonly appear alongside P0174, or share the same subsystem.
- Injector Metering Rail 1 Pressure - Data Valid But Below Normal Operating Range (XPI common rail fuel pressure too low) (SPN 157 FMI 1)
- Fuel Delivery Pressure — Low (SPN 94 FMI 1)
- Injection Rail Pressure — Below Normal (SPN 157 FMI 18)
- Injector Metering Rail 1 Pressure - Data Valid But Above Normal Operating Range (XPI common rail fuel pressure too high) (SPN 157 FMI 0)
- Injector #1 open circuit (SPN 651 FMI 5)
- Injector #2 open circuit (SPN 652 FMI 5)
- Injector #3 open circuit (SPN 653 FMI 5)
- Injector #4 open circuit (SPN 654 FMI 5)
Find a mechanic or related guides
General diagnostic guidance for diesel engines (Cummins, Detroit, PACCAR, Volvo, Mack and more). Not a substitute for a scan-tool diagnosis on your specific truck.