MAN EDC17 Common Rail System Description Manual – D08 D20 D26 Truck & Bus Engines PDF

Description

MAN EDC17 Common Rail System Description for D08, D20 and D26 Engines

This is the MAN Truck & Bus AG system description and repair manual for the Bosch EDC17 control unit and the accumulator injection (Common Rail) fuel system fitted to MAN D08, D20 and D26 diesel engines. Published as document 81.99185-4712, T 175 2nd issue, it is written for technicians who need to understand how the EDC17 electronics interact with the high-pressure fuel circuit, the air system, the exhaust gas aftertreatment and the vehicle CAN network, and then diagnose, test and repair the system correctly.

Every sensor, actuator and hydraulic component in the Common Rail chain is documented: the CP3 high-pressure pump, the proportional fuel valve (MProp), the rail and pressure-limiting valve, the rail pressure sensor, the injectors, the crankshaft and camshaft speed sensors, the charge-air and exhaust gas temperature sensors, the EGR servomotor and E-EGR proportional valve, the turbo charger pulse valves, the EVBec engine brake module, the AdBlue supply module and NOx sensors, the HCI proportional valve, and more. Diagnosis is covered through MAN-cats II, with detailed monitoring windows, test step lists, wiring checks and a full sequence of engine tests.

File Details

• Manual type: System description and repair manual
• Brand: MAN Truck & Bus AG
• Models covered: MAN TGX, TGS, TGL, TGM trucks; MAN Lion’s City, Lion’s Coach, Lion’s Regio, Skyliner, Starliner, Cityliner, Touliner and NEOPLAN H-Bus
• Engines covered: D0834 LFL 66/67/68; D0836 LFL 66/67/68/72/73/74/75/76/77; D0836 LOH 66; D2066 LUH; D2676 LF 34; D2676 LOH 30/31/32; D20/D26 and D08 series
• Language: English
• Page count: 222 pages
• File format: PDF
• Document number: 81.99185-4712
• Edition: 2nd issue (T 175 2nd issue)
• Date: 2013

Chapters Covered

• 1. Introduction
• 2. System Description
• 3. Functional Description
• 4. Description of Components
• 5. Diagnosis with MAN-cats II
• 6. Circuit Diagrams

Introduction (Chapter 1)

Safety instructions, the type overview of trucks and buses/coaches the system description applies to, and the engine overview with output, turbocharging layout and exhaust gas aftertreatment configuration (CRT, SCR, HCI) for each D08, D20 and D26 variant. Read this first to confirm which engine or vehicle variant the rest of the manual applies to.

System Description (Chapter 2)

Explains the principles of accumulator injection: separation of pressurisation from injection, the role of the shared rail, the solenoid-controlled injectors, and how the EDC17 electronics schedule pre-injection, main injection and post-injection. EDC and NoNOx schematics are included, plus overview diagrams of every sensor and actuator on D20/D26 engines with CRT, SCR and HCI, D20/D26 with CRT and SCR only, D0836 LFL 66/67/68, D0834 LFL 66/67, and the CAN network and power supply for D20/D26 and D08.

Functional Description (Chapter 3)

The largest chapter. Each component is documented with its function, its measured values where applicable, and its pin assignment referenced to the A435 EDC17 control unit plug connectors A, C and D. Covered in detail:

• EDC17 control unit A435, including pin assignments for plug connector A (58-pin), C (96-pin) and D (16-pin injector connector)
• CP3 high-pressure pump and Y332 proportional fuel valve (MProp)
• Rail, pressure-limiting valve, B487 rail pressure sensor, Y341 to Y346 injectors
• B488 speed increment sensor and B489 speed segment sensor
• Oil pressure (B104) and oil level (B270) sensors, fuel pressure sensor (B377)
• Air flow meter (B323), charging pressure/temperature sensors (B623, B694), charge air temperature (B123), coolant temperature (B124, B1049)
• EGR temperature sensor (B696), exhaust gas temperature sensors (B561, B562, B634), exhaust gas thermocouples (A1191)
• E-EGR cylinder displacement sensor (B673), E-EGR proportional valve (Y458), EGR servomotor (M289), throttle valve actuator (M119)
• Exhaust gas differential/relative pressure sensor (B695), lambda probe (B322)
• Turbo charger pulse valves (Y340, Y493), Fluidtronic (A1273), E-EGR/EVBec shut-off valve (Y460), low-temperature shut-off/pressure-reducing valve (Y496)
• CRT exhaust throttle valve solenoid (Y398), EVB module (Y355)
• AdBlue supply module (A808), coolant solenoid valve (Y437), AdBlue combination sensor (A1192)
• NOx sensor I (B1055) and NOx sensor II OBD (B994)
• Electronic relay for flame-start system (A1154), fan clutch with speed sensor (A968)
• HCI proportional valve (A1081), metering valve (Y513), shut-off valve (Y514), fuel pressure/temperature sensor (B702), fuel pressure sensor (B703)

Description of Components (Chapter 4)

Component photographs and installation location photographs for each item covered in the functional description, showing what the part looks like on the engine and where it is mounted. Useful when locating a sensor or confirming correct replacement before opening the workshop manual.

Diagnosis with MAN-cats II (Chapter 5)

The diagnostic core of the manual. It opens with the HD-OBD diagnostic socket X200 and its pin assignment, explains the fault storage strategy (SPN, FMI, priority, fault frequency, two environmental conditions) and the FMI status symbols used by MAN-cats II. Two test step lists are provided, one for EDC17 trucks and one for EDC17 bus/coach, with resistance and voltage target values for every sensor, actuator, injector, CAN line and relay, measured at the control unit plug with a breakout adapter.

CAN network troubleshooting is covered separately for D08 engines and for D20/D26 engines, with potential causes and MAN-cats diagnostic messages mapped to SPN/FMI codes. The monitoring chapter documents the live-data windows: temperatures, pressures, rail control, engine speeds, engine values, cylinder correction, status information, PTM messages and requirements, charge air pressure governing, particulate filter, exhaust gas temperatures and pressures, SCR, exhaust gas recirculation and lambda values.

Guided test routines covered in this chapter include:

• Actuator test (charge-air throttle valve, high-pressure wastegate, EGR flap, low-pressure wastegate, exhaust throttle valve)
• Compression test, measuring cylinder compression deviation via starter-motor braking
• Rev-up test, comparing cylinder performance at normal, 800, 1200 and 1600 bar
• Cylinder shut-off test for acoustic injector diagnosis at idle
• High-pressure test for leak detection, using pressure build-up and decay times
• DLR injector test, leak detection by injector coil resistance change
• Pressure-limiting valve open test
• Particulate filter reset routines and particulate filter service regeneration
• HCI system test
• Reset acquired values for particulate filter pressure differential sensor and for pressure-limiting valve
• Reset AdBlue fluid plausibility check
• Injection quantity adjustment (IQA), including read-only transfer before control unit replacement

Circuit Diagrams (Chapter 6)

Brief overview plans for EDC17 electrics on D0836 LOH and on D20/D26 (two pages), plus fuel circuit overview plans for D20/D26 and for D08 with HCI. These give a system-level wiring and fuel-flow reference that supports the diagnosis chapter.

Who This Manual Is For

This MAN EDC17 Common Rail system description is aimed at workshop technicians, fleet maintenance engineers and technically minded owners working on MAN TGX, TGS, TGL and TGM trucks or on MAN Lion’s City, Lion’s Coach and Lion’s Regio buses and coaches fitted with D08, D20 or D26 engines. It is equally useful to anyone diagnosing faults through MAN-cats II, replacing an injector and reprogramming the IQA code, tracing a NOx sensor or EGR fault in the exhaust CAN, testing the high-pressure circuit for leaks, or verifying the correct pinout at the EDC17 control unit before condemning a sensor.

Why It Matters

On a Common Rail diesel, a wrong diagnosis is expensive. The high-pressure side runs at up to 2500 bar, and the difference between a leaking injector, a sticking proportional valve, a tired high-pressure pump and a failing rail pressure sensor is not something you can guess at. This manual provides the pin assignments, the target resistance and voltage values, the rail pressure behaviour, the control unit monitoring windows and the test sequences that let you identify the fault on the first attempt rather than changing parts until the symptom disappears.

The safety chapter is equally relevant. It covers the rules for working on the high-pressure side, the clean-side procedure for opening the fuel system, the risk of dirt ingress (particles over 0.2 mm can cause component failure), and the precautions required for AdBlue handling.

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The manual is delivered as an instant PDF download after payment. No shipping, no waiting. Read it on a laptop, tablet or smartphone in the workshop, print the pages you need for the job at hand, and take the test step lists, pin assignment tables and circuit diagrams straight to the vehicle. One download, unlimited use on your own equipment.