Volvo FM & FH 2009 Wiring Diagram Manual (P/N 20186030)

Volvo Truck Corporation’s Group 37 Wiring Diagram Service Manual, Release 01 (P/N 20186030), covers FM and FH trucks within the chassis ranges listed above. Prepared from designs and methods current through June 2009, it provides electrical reference material supporting professional diagnostics and shop repair workflows.

PDF Search, Bookmarks, and Diagram Detail

Finding circuits and reading labels: Text search works in the indexes and reference lists; labels inside the diagram images are not searchable. Embedded bookmarks link to the main sections and selected reference tables. Small wire, pin, and connector labels require zooming, and many circuit drawings are oriented sideways.

Supplied as one printable, English-language 270-page PDF, including 265 numbered pages and five unnumbered pages: the front cover, foreword, feedback form, blank page, and back cover.

Power, Drivetrain, and Chassis Wiring

The following selected coverage highlights summarize the main electrical areas. Additional drawings include the alcolock start-prevention system and central lubrication circuits.

• Power supply and starting: Battery feeds, starting circuits, power distribution, and standard and ADR main-switch arrangements, with fuse and relay references.

• Engine management and SCR: Engine-specific ECU and sensor wiring, engine-interface connections, and AdBlue dosing and heating circuits.

• Transmission controls: I-shift, Powertronic, gear-selector ECU, manual-gearshift retarder, power takeoff, and differential-lock wiring.

• Braking and suspension: ABS and EBS ECU and modulator circuits, air suspension, bogie lifts, load indication, and electrically controlled steering.

• Cab and trailer equipment: FM/FH LCM lighting, climate-control units, interior lighting, body-builder interfaces, and RIGID and TRACTOR trailer connections.

• Communication networks: J1708/J1587, J1939, and J1939-7/OBD bus drawings, plus Dynafleet and FMS Gateway connections.

This manual is suited to truck electrical technicians who can interpret multi-sheet schematics, connector references, and circuit coordinates.

Selecting the Correct Electrical Variant

Electrical reference scope: The manual supports circuit tracing and component identification during diagnosis and repair. It does not provide step-by-step mechanical repair procedures or diagnostic test sequences.

Individual drawings distinguish engine, market, equipment, and steering-position variants. The diagram guide explains that not every illustrated wire or component is fitted to every vehicle, so the applicable variant matters when selecting a circuit.

The LCM headlight drawings distinguish FH, FM, and FM VAL-BAS2 arrangements. Trailer drawings likewise separate RIGID, TRACTOR, Australian-market, and TREL14 configurations rather than presenting one universal connection layout.

From Control Units to Harness Connections

The component-to-MID cross-reference connects control-unit identifiers with their diagnostic MID numbers. Used alongside the component placement drawings and harness illustrations, it helps technicians relate a control unit to its physical connections and the relevant circuit sheet.

Reference arrows identify the destination diagram, coordinates, component, connector, and pin. Separate ground-connection and connector lists provide another route into the drawings, while the cable-color legend explains single-color and two-color wire markings.

Ground references: A splice can appear on several drawings, while its complete coded ground lead is shown on only one. This distinction matters when following a circuit across sheets.

Main-fuse variants: The FM4 feed differs between battery-box arrangements. Confusing those arrangements can compromise protection of the LCM supply wiring. Before probing circuits or working on high-current components, isolate the electrical supply and follow the applicable workshop safety procedures.

Examples of Main-Fuse Ratings

In power-supply drawing AA, the main preheating fuse FM1 is labeled 125 A, and the main bogie-lift/extra-equipment fuse FM2 is labeled 200 A. The fuse reference list identifies the protected equipment and links these identifiers back to the circuit drawings.