What does it mean?
This code is a mechanical complaint rather than a circuit one: the pressure measured in the bank 2 fuel rail is below the minimum the module requires. On a direct injection V engine each bank has its own high pressure pump and rail, and the module commands a target pressure through the volume control valve while watching the bank 2 sensor as feedback.
When actual pressure stays under the allowed tolerance while the pump is being asked for maximum output, the module concludes that bank cannot be supplied and stores the code. Injector pulse widths are calculated for the expected pressure, so a low bank 2 rail leans out only those cylinders and creates a bank specific misfire the driver can often feel. The module protects the engine by limiting torque and, in severe cases, by cutting power sharply.
Symptoms
- MIL (check engine lamp) on with a clear loss of power or limp mode
- Severe misfire and rough running felt on one side of the engine
- Long cranking, hard starting or a no-start when pressure cannot build
- Hesitation and a flat spot when accelerating hard
- Stalling at idle or when the throttle is released
- Fuel odour or a visible leak where a fitting or line is at fault
Likely causes
- Worn or failing bank 2 high pressure pump, often with a worn cam follower or drive lobe
- Faulty volume control valve on the bank 2 pump, stuck or leaking internally
- Leaking injector on bank 2 bleeding rail pressure back to the return
- Leaking high pressure fitting, rail seal or line on that bank
- Restricted low pressure supply to the bank 2 high pressure pump, including a blocked filter or a weak lift pump
- Pressure relief valve on the bank 2 rail opening early or failing to reseat
- Bank 2 rail pressure sensor reading low while actual pressure is correct
How to fix it
- Graph commanded and actual bank 2 rail pressure alongside pump duty during cranking, at idle and under load, and compare with bank 1
- Verify the sensor first by comparing its reading against actual pressure with the manufacturer approved method, so a drifted sensor is ruled out
- Check the low pressure supply to the bank 2 high pressure pump for correct pressure and volume, and replace a filter that is at or past its interval
- Perform a pressure hold test after shutdown; a rail that falls much faster than bank 1 indicates a leaking injector, relief valve or fitting
- Command the bank 2 volume control valve with a scan tool and confirm the rail responds; a valve that produces no change is a strong suspect
- Inspect the high pressure pump and its drive, including the cam follower, for wear and metal debris, and inspect all fittings for leakage
- Repair or replace the failed component, always following the depressurising and cleanliness procedures for a high pressure fuel system, then verify the rail holds the commanded pressure across the load range