Volvo FM Factory Workshop Manual. Wiring Diagram

A comprehensive factory repair and maintenance manual for Volvo FM trucks. Includes full technical documentation, official procedures and specifications approved by the manufacturer. Designed for professional mechanics, service engineers and technicians.

Volvo FM13 Drive 6×4

• Detailed instructions for engine, transmission, brake system, suspension, steering
• Wiring diagrams and troubleshooting guide
• Torque tables and tightening sequence
• EBS, VECU, TECU, MID protocols and parameters
• Step-by-step procedures for disassembling, assembling and replacing components
• SCR, EGR, AdBlue, DPF maintenance
• Pressure, cooling, fluid level checks

• General>>
• Volvo Home Page>>

CHID A678743– CHID B532897– CHID CKD882147–

FM, FH CHID A622782– FM, FH CHID B433164–

1. 🔌 Oxidation or damage to the ground (grounds)

Symptoms: headlights do not turn on, instrument panel failures, strange errors on CAN

Reason: Corrosion of under-cabin and chassis ground connections

Solution: checking, cleaning, processing and tightening the "grounds"

2. 🔋 Failure of the VECU (Vehicle Electronic Control Unit) module

Symptoms: wipers, windows, lights - work unstably or do not work

Reason: chip failure in VECU or damage to the wiring to it

Solution: diagnostics via Volvo Tech Tool, repair or replacement of the unit is possible

3. 🧠 Problems with the CAN bus

Symptoms: partial loss of communication between units, MID errors 128, 140, 144

Reason: open CAN line, short circuit, resistance not 60 Ohm

Solution: multimeter check, shielding/harness repair

4. 💡 Taillight and connector issues

Symptoms: brake lights, backlight, turn signals don't work

Reason: dirt and corrosion in connectors on rear fender or under frame

Solution: cleaning, replacing connectors, sealing with sealant

5. 🌡️ Coolant or air temperature sensor failures

Symptoms: fan turns on constantly, cooling errors, engine "goes into protection"

Reason: open or short circuit in sensor circuit

Solution: replacing sensor, checking voltage/resistance

6. 📉 Gas pedal errors (APS/MID 128 SID 1 position sensor)

Symptoms: engine doesn't respond to gas, floating speed

Reason: APS potentiometer failure

Solution: check on diagnostics, replace sensor APS on the pedal

7. 🔄 Gearbox position sensor issues (if I-Shift)

Symptoms: gear does not engage, MID 130 SID 70/71 errors

Reason: damaged selector position sensor or gear selection clutch

Solution: sensor replacement or actuator repair

8. ❄️ Random fan activation, climate control glitches

Symptoms: climate "lives its own life"

Reason: failure in the heating control unit (sometimes due to the interior sensor)

Solution: resistance check, unit reset, sometimes replacement