MAN Nutzfahrzeuge Aktiengesellschaft — Troubleshooting chart

Troubleshooting chart x = Possible o = Probable 33 1. EDC self-diagnosis or flash code output 2. Starter turns over engine only slowly or not at all 3. Starter turns, engine does not start, engine does not start / difficult to start when cold 4. Engine stalls (dies) during operation, no longer starts (starter turns), engine does not start / starts with difficulty when hot 5. Sudden, temporary engine shut-down, engine does not reach full revs 6. Engine only runs at idle speed, no throttle response 7. Engine only runs at increased idle speed, no throttle response 8. Rated engine speed distinctly reduced (even under no load) 9. Reduced output in all ranges 10.

Irregular engine operation, traction loss 11. Unstable idle speed, engine hunting, misfiring, knocking in engine 12. Engine judder 13. Unusual combustion noise 14. Excessive smoke emission: White smoke / blue smoke 15. Excessive smoke emission: Black smoke 16. Engine temperature too high (coolant loss) 17. Fuel consumption too high 18. Lubricating oil pressure too low 19. Lubricating oil pressure too high 20. Lubricating oil consumption too high 21. Engine too “loud” / mechanical noise 22. Idle speed cannot be adjusted with idle speed operating unit Possible causes 2. Starter turns over engine only slowly or not at all 3.

Starter turns, engine does not start, engine does not start / difficult to start when cold 4. Engine stalls (dies) during operation, no longer starts (starter turns), engine does not start / starts with difficulty when hot 5. Sudden, temporary engine shut-down, engine does not reach full revs 6. Engine only runs at idle speed, no throttle response 7. Engine only runs at increased idle speed, no throttle response 8. Rated engine speed distinctly reduced (even under no load) 9. Reduced output in all ranges 10. Irregular engine operation, traction loss 11. Unstable idle speed, engine hunting, misfiring, knocking in engine 12. Engine judder 13. Unusual combustion noise 14.

Excessive smoke emission: White smoke / blue smoke 15. Excessive smoke emission: Black smoke 16. Engine temperature too high (coolant loss) 17. Fuel consumption too high 18. Lubricating oil pressure too low 19. Lubricating oil pressure too high 20. Lubricating oil consumption too high 21. Engine too “loud” / mechanical noise 22. Idle speed cannot be adjusted with idle speed operating unit Possible causes 4. Engine stalls (dies) during operation, no longer starts (starter turns), engine does not start / starts with difficulty when hot 5. Sudden, temporary engine shut-down, engine does not reach full revs 6. Engine only runs at idle speed, no throttle response 7.

Engine only runs at increased idle speed, no throttle response 8. Rated engine speed distinctly reduced (even under no load) 9. Reduced output in all ranges 10. Irregular engine operation, traction loss 11. Unstable idle speed, engine hunting, misfiring, knocking in engine 12. Engine judder 13. Unusual combustion noise 14. Excessive smoke emission: White smoke / blue smoke 15. Excessive smoke emission: Black smoke 16. Engine temperature too high (coolant loss) 17. Fuel consumption too high 18. Lubricating oil pressure too low 19. Lubricating oil pressure too high 20. Lubricating oil consumption too high 21. Engine too “loud” / mechanical noise 22.

Idle speed cannot be adjusted with idle speed operating unit Possible causes 6. Engine only runs at idle speed, no throttle response 7. Engine only runs at increased idle speed, no throttle response 8. Rated engine speed distinctly reduced (even under no load) 9. Reduced output in all ranges 10. Irregular engine operation, traction loss 11. Unstable idle speed, engine hunting, misfiring, knocking in engine 12. Engine judder 13. Unusual combustion noise 14. Excessive smoke emission: White smoke / blue smoke 15. Excessive smoke emission: Black smoke 16. Engine temperature too high (coolant loss) 17. Fuel consumption too high 18. Lubricating oil pressure too low 19.

Lubricating oil pressure too high 20. Lubricating oil consumption too high 21. Engine too “loud” / mechanical noise 22. Idle speed cannot be adjusted with idle speed operating unit Possible causes 8. Rated engine speed distinctly reduced (even under no load) 9. Reduced output in all ranges 10. Irregular engine operation, traction loss 11. Unstable idle speed, engine hunting, misfiring, knocking in engine 12. Engine judder 13. Unusual combustion noise 14. Excessive smoke emission: White smoke / blue smoke 15. Excessive smoke emission: Black smoke 16. Engine temperature too high (coolant loss) 17. Fuel consumption too high 18. Lubricating oil pressure too low 19.

Lubricating oil pressure too high 20. Lubricating oil consumption too high 21. Engine too “loud” / mechanical noise 22. Idle speed cannot be adjusted with idle speed operating unit Possible causes 10. Irregular engine operation, traction loss 11. Unstable idle speed, engine hunting, misfiring, knocking in engine 12. Engine judder 13. Unusual combustion noise 14. Excessive smoke emission: White smoke / blue smoke 15. Excessive smoke emission: Black smoke 16. Engine temperature too high (coolant loss) 17. Fuel consumption too high 18. Lubricating oil pressure too low 19. Lubricating oil pressure too high 20. Lubricating oil consumption too high 21. Engine too “loud” / mechanical noise 22.

Idle speed cannot be adjusted with idle speed operating unit Possible causes 12. Engine judder 13. Unusual combustion noise 14. Excessive smoke emission: White smoke / blue smoke 15. Excessive smoke emission: Black smoke 16. Engine temperature too high (coolant loss) 17. Fuel consumption too high 18. Lubricating oil pressure too low 19. Lubricating oil pressure too high 20. Lubricating oil consumption too high 21. Engine too “loud” / mechanical noise 22. Idle speed cannot be adjusted with idle speed operating unit Possible causes 14. Excessive smoke emission: White smoke / blue smoke 15. Excessive smoke emission: Black smoke 16. Engine temperature too high (coolant loss) 17.

Fuel consumption too high 18. Lubricating oil pressure too low 19. Lubricating oil pressure too high 20. Lubricating oil consumption too high 21. Engine too “loud” / mechanical noise 22. Idle speed cannot be adjusted with idle speed operating unit Possible causes 16. Engine temperature too high (coolant loss) 17. Fuel consumption too high 18. Lubricating oil pressure too low 19. Lubricating oil pressure too high 20. Lubricating oil consumption too high 21. Engine too “loud” / mechanical noise 22. Idle speed cannot be adjusted with idle speed operating unit Possible causes 18. Lubricating oil pressure too low 19. Lubricating oil pressure too high 20. Lubricating oil consumption too high 21.

Engine too “loud” / mechanical noise 22. Idle speed cannot be adjusted with idle speed operating unit Possible causes 20. Lubricating oil consumption too high 21. Engine too “loud” / mechanical noise 22. Idle speed cannot be adjusted with idle speed operating unit Possible causes 22. Idle speed cannot be adjusted with idle speed operating unit Possible causes x x x x x x x x Fuel low pressure system: Fuel lines leaking, broken, clogged x x x x x x x Fuel low pressure system: Air in system (turn on ignition when bleeding system) x x x x x x x x x Fuel low pressure system: Fuel pump, overflow valve, main filter x x x x x o x x Fuel high pressure system:

Jets defective / clogged / leaking / coked x x x x o Fuel high pressure system: Pressure lines – constriction, cavitation, leaking x x o x x x x o Fuel high pressure system: Injection pump worn / set incorrectly o x o o Fuel high pressure system: Injection pump constant-pressure control valve / return flow restrictor defective x x x x o x EHAB defective, drive faulty, Relay K2 defective o o o x o x x x Injection pump-engine allocation: Start of delivery incorrect (basic installation), start of delivery set incorrectly x x x x o x o Injection pump – controller: Stiff movement – fuel delivery controller (control deviation) x x x x o Control rod position transducer in controller:

Connection lines, break, short-circuit o o o Control rod position transducer in controller: Set incorrectly x x o Control rod position transducer in controller: Capacitance reserve of wiring harness too low (e.g. water penetrated wiring harness) x o x o o Injection pump: Delivery set incorrectly / uniform delivery, lower idle speed set too low x o x x x Delivery actuating solenoid in controller: Connection lines, break, short-circuit x x x x x o Pedal value transmitter (hand throttle signal) defective: connecting cables, short-circuit, interruption With 4–20 mA throttle lever signal:

– Connection cable for 4–20 mA throttle lever signal interrupted – Throttle lever system defective (no 4–20 mA signal present) – Wire jumpers at Pins 11/13, 12/14 in plug X9 are missing – EDC control box 51.11615–7169 is defective x x EDC rpm sensor defective, implausible with auxiliary rpm sensor, line defective x x o EDC rpm sensor, polarity reversed x x EDC auxiliary rpm sensor defective, implausible with rpm sensor, line defective x x x x o o o o EDC detects incorrect engine speed (interference signal on rpm sensor line) x x x x o Both rpm sensors defective, line defective x x x EDC turbo pressure sensor:

Defective, incorrect, implausible with atmospheric pressure sensor, line defective x x o x Exhaust turbocharger leaking or defective x Turbine and compressor rotor in turbocharger dirty (out-of-balance, irregular running) x Intercooler leaking, defective x x Charge-air preheater defective