Direct answer to the question - The DAF XF 105 uses the EAS-2 Selective Catalytic Reduction SCR after-treatment system, which meters Diesel Exhaust Fluid DEF AdBlue into the exhaust to meet Euro 4 & 5 emission limits. - The complete AdBlue wiring diagram is contained in DAF electrical drawing 04A-1 EAS section and is available in the official XF 105 Electrical System Diagrams or via DAVIEDAF RMI. - Typical service tasks: keep quality DEF 32.5 % urea, replace the in-tank filter yearly, inspect pump wiring and NOx-sensor connectors for corrosion, and use DAVIE or an SCR-capable scan tool to run the “pressure build-up” and “dosing-quantity” tests. Detailed problem analysis 1. System architecture EAS-2 • AdBlue tank module – Integrated level temperature quality sensor 5-wire – Immersion heater and 9 bar centrifugal pump two-wire power + CAN • Supply line with electrical trace heating monitored by EAS ECU • Dosing unit BoschContinental on the exhaust – single-wire injector + heater + pressure sensor • Upstream & downstream NOx sensors CAN-based • SCR catalyst brick • EAS ECU sometimes combined with engine ECU on later builds communicating on 250 kbits chassis-CAN 2. Key electrical data Euro 5 build codes • Pump current 8-12 A while priming • Line tank heaters 150-200 W total switched at –8 °C, cut-out at +15 °C • CAN differential 1.8–3.0 V, 120 Ω termination inside ECU & tail-lamp harness 3. Common faults and their fingerprints | Fault domain | Observable symptom | Frequent DTCs DAFDAVIE | Quick field check | |--------------|--------------------|---------------------------|-------------------| | NOx sensor downstream most common | MIL + “Emission after-treatment fault”, high DEF use | P2200, P2202, P20EE | Live NOx values identical prepost, or stuck 0 ppm | | Pump supply module | No pressure rise during priming, engine derate 25 % | P204F, P207F | Command “Pressure build-up” →

DAF XF 105 AdBlue EAS-2 SCR System: Wiring, Common Faults, Service Tips

User question

Adblue daf xf 105

Artificial Intelligence Response

Direct answer to the question

The DAF XF 105 uses the EAS-2 Selective Catalytic Reduction (SCR) after-treatment system, which meters Diesel Exhaust Fluid (DEF / AdBlue) into the exhaust to meet Euro 4 & 5 emission limits.
The complete AdBlue wiring diagram is contained in DAF electrical drawing 04A-1 (EAS section) and is available in the official XF 105 Electrical System Diagrams or via DAVIE/DAF RMI.
Typical service tasks: keep quality DEF (32.5 % urea), replace the in-tank filter yearly, inspect pump wiring and NOx-sensor connectors for corrosion, and use DAVIE or an SCR-capable scan tool to run the “pressure build-up” and “dosing-quantity” tests.

Detailed problem analysis

System architecture (EAS-2)
• AdBlue tank module
– Integrated level / temperature / quality sensor (5-wire)
– Immersion heater and 9 bar centrifugal pump (two-wire power + CAN)
• Supply line with electrical trace heating (monitored by EAS ECU)
• Dosing unit (Bosch/Continental) on the exhaust – single-wire injector + heater + pressure sensor
• Upstream & downstream NOx sensors (CAN-based)
• SCR catalyst brick
• EAS ECU (sometimes combined with engine ECU on later builds) communicating on 250 kbit/s chassis-CAN
Key electrical data (Euro 5 build codes)
• Pump current 8-12 A while priming
• Line / tank heaters 150-200 W total (switched at –8 °C, cut-out at +15 °C)
• CAN differential 1.8–3.0 V, 120 Ω termination inside ECU & tail-lamp harness
Common faults and their fingerprints

Fault domain	Observable symptom	Frequent DTCs (DAF/DAVIE)	Quick field check
NOx sensor (downstream most common)	MIL + “Emission after-treatment fault”, high DEF use	P2200, P2202, P20EE	Live NOx values identical pre/post, or stuck 0 ppm
Pump / supply module	No pressure rise during priming, engine derate 25 %	P204F, P207F	Command “Pressure build-up” → <3 bar
Line / tank heater	Derate only in freezing weather	P20E8, P20E9	Clamp-meter: no heater current with coolant <0 °C
Dosing injector leak/block	White crystals on pipe or exhaust	P208E, P208A	60-s “dosing quantity test” ≤80 ml or >130 ml
Harness corrosion @ pump connector 123F	Intermittent CAN errors	U029D, U029E	Wiggle test, spray with contact-cleaner

Fuses & relays
• F47 (10 A) – pump/heater 1 supply
• F48 (30 A) – main heater feed
• R24 – pump relay (coil fed from ignition-KL15)
Wiring-diagram navigation (drawing 04A-1)
• Connector 123F (8-pin black) – tank module
– 1 = Ground (BN) – 2 = +12 V (RD) – 3/4 = CAN-H/L (YE/GN) – 5 = level – 6 = quality – 7 = temp – 8 = heater supply
• Connector 124F (3-pin black) – dosing valve heater
• Connector 129F (12-pin) – EAS ECU plug A

Current information and trends

2022-on Euro VI DAFs switch to EAS-4 with integrated pump/doser (“one-box”); however many fleets still refit XF 105 pump modules (OE 1699840) due to parts availability.
Updated Bosch NOx sensors carry suffix –10, using stainless-steel venting to reduce moisture ingress—a recommended retrofit during sensor replacement.
Remote telematics (DAF Connect) can now log SCR efficiency and predict dosing faults, cutting unscheduled downtime.

Supporting explanations and details

AdBlue crystallises at –11 °C; the EAS ECU therefore keeps heaters powered for up to 45 min after key-off to purge lines. If battery voltage is low (<11.5 V) priming may abort—verify alternator output before condemning the pump.
Dosing quantity test: Place a graduated 500 ml beaker under the injector, run the “Service-function → AdBlue dosing” for 60 s @ idle; spec 95 ± 15 ml. Less = blockage, more = leaking pintle.
Fluid quality: a handheld optical refractometer (DEF scale) should read 31.8–33.2 %. Contaminated DEF (oil/diesel) attacks pump seals; always draw fresh sample mid-tank, not from filler neck.

Ethical and legal aspects

Disabling or “emulating” the AdBlue system violates EU Regulation 2018/858, voids Whole Vehicle Type Approval, and can incur fleet fines. As engineers we must restore OEM functionality, not bypass it.
DEF is mildly alkaline; wear gloves, rinse spills, and never store in galvanised containers (zinc contamination poisons the catalyst).

Practical guidelines

Annual/100 000 km service
• Drain tank, flush with de-ionised water, replace 10 µm cartridge filter in pump head.
• Update ECU software (DAF campaign EAS-2_22-03 mitigates false P20EE).
Cold-weather preparation
• Verify coolant‐to-DEF heat exchanger (where fitted) is not bypassed.
• Run heater self-test in DAVIE; resistance of line heater ≈1.3 Ω/m @ 20 °C.
Fault isolation hierarchy
a) Retrieve codes → b) visual leak/connector check → c) run guided DAVIE tests → d) measure voltage/current → e) component swap.

Possible disclaimers or additional notes

Early 2006-2007 XF 105s use a separate SCR-CAN gateway; pin numbers above apply to 2008-2013 “single-ECU” layout—always cross-check chassis number in DAVIE.
Non-OEM NOx sensors often draw >11 W heater power, triggering “NOx sensor heater performance” despite being new.

Suggestions for further research

Compare EAS-2 vs EAS-3 dosing strategies (OBD-C vs OBD-D) to optimise DEF consumption.
Explore predictive maintenance using NOx conversion efficiency trends.
Investigate ammonia-slip catalyst retrofits to allow leaner calibration and fuel saving.

Brief summary

The DAF XF 105 AdBlue (EAS-2) system relies on a tank-mounted pump, heated delivery line, dosing injector and dual NOx sensing under ECU control. Electrical troubleshooting starts with wiring diagram 04A-1, inspection of fuses F47/F48, and live-data tests in DAVIE. Most field failures stem from pump pressure loss, downstream NOx sensor aging, or harness corrosion—faults that can be accurately isolated with systematic pressure, dosing and heater checks. Maintain correct-grade DEF, replace the in-tank filter yearly, and keep connectors dry to ensure long service life and legal emissions compliance.

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