Accumulator pressure is excessively below command.
Warning! The fuel system has a very high pressure, up to 2000 bar. The fuel system must be depressurised before any work is carried out. The system should always be treated as pressurised, even when the engine is switched off. Wear protective gloves and goggles. For more information about safety when working with the fuel system, refer to service information "XPI fuel system". Make the investigation in the following order: 1. If there are other fault codes on any injector, troubleshoot the injectors. 2. If there is any fault code about leakage in the high pressure side, it must be rectified first. 3. Check how large the leak is; follow Checking for internal leaks. 4. Check the safety valve; follow Leak testing the safety valve. 5. Check injector for internal leakage; follow Fuel leak test. 6. Run "High pressure fuel system leakage workshop test" and follow the instructions to check if there is any leakage in the high pressure fuel system. 7. Troubleshoot the high pressure side according to the instructions, see Workshop manual, 03-00 Fuel and exhaust system assembly, 03:14-01 Fuel system XPI troubleshooting. 8. Troubleshoot the low pressure side according to the instructions, see Workshop manual, 03-00 Fuel and exhaust system assembly, 03:14-01 Fuel system XPI troubleshooting. 9. Troubleshoot the high pressure pump according to the instructions, see Workshop manual, 03-00 Fuel and exhaust system assembly, 03:14-01 Fuel system XPI troubleshooting.
What you'll see
There may be black smoke from the engine. When this fault code is active, engine power is reduced and the EGR system is deactivated. The fault code cannot be deleted when it is active.
System reaction
MI warning lamp MI_B1 and yellow warning lamp
Diagnostic depth
Fuel pressure in the accumulator is lower than requested.
Possible causes: • Internal or external leakage in the high pressure side. • Damaged fuel lines • Insufficient fuel supply from the low pressure side. • Fault in the high pressure pump.