MAN Euro 6 EDC 2 04547-01 SCR/AdBlue Dosing Fault, Symptoms, and Fixes

User question

Cod eroare edc 2 04547-01 man

Artificial Intelligence Response

Direct answer to the question

• Meaning: On MAN Euro 6 trucks, fault EDC 2 04547-01 indicates an SCR/AdBlue (DEF) dosing system malfunction detected by the engine ECU (EDC). In practice it means dosing is inhibited or not meeting commanded operation.
• Key points:
  • Often accompanies SCR codes such as 505022-01 (AdBlue system fault) and 505556-10 (return line blocked).
  • If active for long, it can trigger limp/creep mode with severe power/speed limitation.
  • Typical root causes: electrical supply/ground or CAN issues at the dosing module (“NONOX”), clogged or frozen lines/injector, failed pump/dosing unit, or sensor faults (e.g., NOx) that force dosing shutdown.

Detailed problem analysis

• What the EDC is flagging:
  • The EDC monitors the SCR dosing unit’s electrical state (supply, current draw, actuator feedback) and hydraulic performance (pressure build/hold, injector actuation). Code 04547 with suffix “-01” on MAN generally denotes an electrical/functional deviation below expected range or a short-to-ground/underrange condition in the dosing subsystem. When the controller cannot safely dose, it sets this EDC code and may also log SCR subsystem codes.
• Why it happens:
  • Electrical: Undervoltage at the dosing module (weak batteries, corroded connectors, damaged harness near the AdBlue tank/frame), poor ground, blown/weak fuse or relay, wiring chafing, water ingress in connectors.
  • Hydraulic/mechanical: Crystallized DEF blocking the injector/nozzle or return, clogged internal filter of the dosing module, frozen lines/heater failure, air leaks causing pressure decay, worn pump.
  • Sensor/controls: Upstream/downstream NOx sensor implausibility, exhaust temperature preconditions not met (e.g., too cold), ECU strategy halting dosing to protect the catalyst.
• Symptom set you’ll see:
  • MIL/EDC lamp on, SCR warning; countdowns to torque/speed restriction.
  • AdBlue consumption abnormally low; visible DEF crystallization around the injector outlet.
  • Possible companion DTCs in SCR/NOx/temperature circuits (very important for pinpointing root cause).
• Note on conflicting mappings you may find:
  • Some general code lists or offline references map “4547/04547” to EGR cooler bypass or generic exhaust temperature items. For MAN Euro 6 field cases, 04547-xx is overwhelmingly tied to AdBlue dosing faults. Treat EGR/EGT interpretations with caution unless supported by the truck’s full DTC set and live data.

Current information and trends

• Field experience on MAN Euro 6 platforms links EDC 2 04547-01 with active AdBlue system failure and, if ignored, a progression to creep mode around 20 km/h. Threads and service notes frequently show it paired with SCR 505022-01 and 505556-10, pointing to dosing interruption and return-line blockage.
• Industry trend: OEMs increasingly implement stricter de-rate strategies after detected SCR inhibition; software updates may refine thresholds and test routines. After repair, some ECUs require a complete SCR service routine and drive cycle before the restriction is lifted.

Supporting explanations and details

• SCR (Selective Catalytic Reduction) basics:
  • The dosing module pumps DEF to a target pressure and meters it via the injector into the exhaust upstream of the SCR catalyst. Proper operation requires adequate battery voltage, heated/defrosted lines, correct DEF concentration (per ISO 22241), correct exhaust temperatures, and valid NOx feedback.
• What “-01” typically implies on MAN:
  • Manufacturer-specific FMI indicating signal low/underrange or short-to-ground in the monitored circuit, or a measured performance notably below commanded (e.g., pressure not building as expected, injector current low).

Ethical and legal aspects

• Do not bypass or delete the AdBlue/SCR system. Emissions tampering is illegal in the EU and U.S., risks fines, inspection failure, and warranty/insurance issues. Always pursue root-cause repair with compliant parts and procedures.

Practical guidelines

• Before you start
  • Record all active and stored DTCs in EDC and SCR controllers; note freeze-frame data and mileages to derate.
  • Verify battery health and charging system; low system voltage is a common trigger.
• Quick checks (5–15 minutes)
  • Visual: Inspect DEF injector tip for crystallization; check lines for kinks/leaks; confirm tank has quality DEF (use a refractometer if available).
  • Electrical: Wiggle-test and inspect harness/connectors at the dosing module on the frame/tank; check for moisture/corrosion; verify module ground integrity.
  • Fuses/relays: Check the AdBlue pump/module feed fuse and relay per your chassis fuse layout.
• Guided diagnostics (with MAN-cats or equivalent)
  • Run “DEF pump prime/pressure build” test: ensure pressure rises promptly and holds (a rapid decay suggests leaks, non-return valve, or injector stuck open; failure to build suggests pump/filter/blockage or supply fault).
  • Run “Doser functional test” and “Leak/return test”: distinguishes injector blockage vs. return obstruction (often tied to 505556-10).
  • Check heater line states and current draw in cold ambient; verify thaw strategy if ambient < 0°C.
  • Read upstream/downstream NOx values and SCR efficiency; implausible feedback can command dosing inhibition.
  • Monitor dosing module supply voltage at the connector under load; voltage drop > ~1 V from battery indicates wiring/connector issues.
• Likely fixes (ordered by occurrence)
  • Repair corroded pins/grounds or damaged harness near the tank and frame crossmembers.
  • Replace/clean clogged DEF injector and flush lines; service/replace the dosing module filter if applicable.
  • Replace failing dosing pump/module when pressure tests fail and power/ground are confirmed good.
  • Address heater line failures (open-circuit heaters or temperature sensor faults causing persistent freezing).
  • Replace faulty NOx sensor(s) only when confirmed by plausibility tests and DTCs.
• After repair
  • Clear DTCs, perform the OEM SCR service routine, and complete a warm drive cycle at sustained load so the ECU can verify SCR performance and lift any active restriction.

Possible disclaimers or additional notes

• MAN uses variant-specific code-books; exact “-01” semantics can differ slightly by ECU software. Always interpret 04547-01 alongside concurrent SCR/NOx/EGT codes and live data.
• If your truck previously had AdBlue faults and 04547-01 reappears intermittently, suspect borderline voltage/ground or internal pump wear.

Suggestions for further research

• Provide the truck model (e.g., TGX/TGS), year, VIN last 7, all current DTCs, ambient temperature conditions, and what tests you’ve already run. With that, I can tailor pinouts, expected measurements at the dosing module connector, and a step-by-step test plan for your exact variant.
• If available, check your service portal for ECU software updates addressing SCR diagnostics robustness.

Brief summary

• EDC 2 04547-01 on MAN Euro 6 points to an SCR/AdBlue dosing system fault that, if active, will escalate to severe derate. Start with power/ground integrity and quick visual checks, then run OEM pressure, leak, and doser tests to separate electrical from hydraulic causes. Repair the verified root cause, avoid any tampering, clear codes, and complete the SCR verification drive cycle to restore full performance.