Mercedes Benz

Internal fault in control unit (P0221) Internal fault in control unit (P0221) Possible cause: ­ B37 (Accelerator pedal sensor) ­ N3/10 (ME­SFI [ME] control unit) Affected functions: ­ Engine diagnosis ­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­ Test 1: Test control unit. Test 2: Check component B37 (Accelerator pedal sensor). 1. Test control unit. Test control unit. Possible cause and remedy ­ ­ Erase fault memory and start engine. Reread fault memory of control unit N3/10 (ME­SFI [ME] control unit).If fault reoccurs, replace component N3/10 (ME­SFI [ME] control unit). Read coding and transfer to the new control unit.End of test 2. Check component B37 (Accelerator pedal sensor). Test 2.1: Check component B37 (Accelerator pedal sensor) using actual value. Test 2.2: Check power supply of component B37 (Accelerator pedal sensor). 2.1. Check component B37 (Accelerator pedal sensor) using actual value. Test sequence ­ Switch on ignition. Status of the releva...