MAN AdBlue Problems
Expert diagnostics for MAN SCR systems. If your MAN has an AdBlue warning, NOx sensor fault, engine derate, or has started a restart countdown, we can help identify the root cause using dealer-level diagnostic equipment.
Common MAN SCR Faults
MAN commercial vehicles use SCR (Selective Catalytic Reduction) systems to meet Euro 5 and Euro 6 emissions standards. NOx sensors, the AdBlue dosing pump, dosing injector, and SCR catalyst are the components most commonly implicated in faults. We diagnose all fault types using dealer-level equipment and live data analysis — not code-reading alone.
NOx Sensor Faults
The upstream and downstream NOx sensors are the most common failure point on MAN trucks. They fail from soot contamination, connector corrosion, and thermal damage. A sensor fault code may also indicate wiring problems or a poorly performing catalyst rather than sensor failure — live data analysis is essential before replacing any part.
Dosing Pump Failures
The AdBlue pump must maintain correct pressure for accurate dosing. Pressure faults can result from pump wear, internal leaks, air ingestion, or blockages. Actuator testing with our diagnostic equipment measures real pump output against the expected value.
Derate & Countdown
MAN trucks implement engine derate and a "starts remaining" countdown when SCR faults reach a critical threshold. The countdown cannot be reset by clearing codes with a generic scanner — proper diagnostic access is required.
Manufacturer Diagnostic Profile
Models covered
TGX · TGS · TGM · TGL
Engine families
D26 · D20 · D15 · D08
Diagnostic equipment
MAN-cats III
Terminology checked
HDS and EDC fault-state information, with SAE P-codes where presented
MAN dealer diagnostic screen
Services
- Complete SCR Diagnostics
- NOx Sensor Testing & Wiring Checks
- AdBlue Pump Pressure Testing
- Dosing Injector Actuator Testing
- Countdown Reset (with fault resolution)
- ECU Software Verification
Vehicle Immobilised?
If your MAN has reached zero restarts, call us directly.
01302 20202907929 765432Fault Codes — MAN HDS / EDC / SCR
Common MAN AdBlue & SCR Fault Codes
MAN HDS/EDC diagnosis needs the exact truck, controller and fault-state information. A code points to a monitored system, not an automatic replacement part.
MAN diagnostic labels depend on vehicle generation and controller. SAE P-codes below are included only when an affected vehicle actually presents them; they are not described as MAN-proprietary codes.
| Fault code | System | Common description | Possible causes |
|---|---|---|---|
| 01761 | Urea tank | Urea fill-level tank fault context | Level condition, level-sensor signal, wiring or connector concern |
| P20E8 | Reductant pressure | Reductant pressure too low when presented as an SAE P-code | Pump delivery, restriction, leak, crystallisation or pressure data |
| P20EE | SCR efficiency | SCR NOx efficiency below threshold when presented as an SAE P-code | NOx data, dosing, fluid quality, temperature or catalyst performance |
01761
MAN 01761 — urea tank fault context
What it means
The diagnostic system has identified the urea-tank area for investigation. It does not by itself distinguish a genuine low-level condition from a sensor or circuit concern.
Common causes
- •AdBlue level condition
- •Level-sensor signal
- •Tank connector or wiring condition
- •Controller fault context requiring HDS review
Symptoms
AdBlue warning · Emissions message · Reduced-power strategy on affected systems
What ECUFLASH checks
ECUFLASH records the exact HDS/EDC fault status, confirms tank data and then checks the relevant wiring, supply and SCR evidence before repair advice.
Source basis: MAN truck fault-code data compendium · SAE/ISO OBD generic-code terminology, used only where the vehicle presents SAE P-codes.