MAN TGS/TGX Wiring Diagram. Electrical System

Complete guide to the electrical circuit diagram for MAN TGS and MAN TGX trucks. The document contains detailed wiring diagrams, descriptions of the on-board network components, connections and control units. Suitable for diagnostics, repair and maintenance of the electrical system of modern MAN models.

📘 What does the wiring diagram include:

• Wiring diagrams and connections for D20, D26, D38 engines
• Pinout of connectors, description of fuses and relays
• CAN bus, ECU/TCU/BCU control units
• Lighting, instrument panel, driver assistance systems (ESP, ABS, EBS)
• Connection of additional consumers: air conditioner, heater, Webasto
• Color or black and white diagrams with contact numbers and designations

🚛 For which MAN models:

• MAN TGS 18.xxx, 26.xxx, 33.xxx, 41.xxx
• MAN TGX 18.xxx, 24.xxx, 26.xxx, 28.xxx
• Euro 4 / Euro 5 / Euro 6
• Configurations 4x2, 6x4, 8x4, etc.

• A Power supply
• B Remote control
• C Control lamp

A100 Central Electric Network

A143 ECAS control unit

A221 Remote control ECAS

A302 Central Computer 2

A407 Instrument panel

F164 ECAS fuse (terminal 30)

F375 Cabin fuse outside (terminal 15)

H394 ECAS Malfunction/Warning Indicator Lamp

X770 ECAS plug connection, suspension level II

X1644 Cabin ground point near central electrical network

1. 🔋 CAN bus failures (J1939/J1587)

Symptoms: communication error between modules, sudden loss of communication with ECU, TCU, BCU

Causes: poor contacts, corrosion on connectors, pinched wires

Solution: checking the resistance between CAN-H and CAN-L, cleaning and sealing the connectors

2. 🔌 Oxidation of connectors and wiring

Especially in areas: front of the cabin, battery compartment, under the seats

Symptoms: chaotic errors on the dashboard, non-working sensors, failure of headlights or instruments

Solution: inspection of connectors, cleaning, lubrication, replacement of damaged harnesses

3. 💡 Problems with lighting and taillights

Symptoms: blinking headlights, brake light does not work, "lamp "burned out" with the working lamp

Causes: damaged rear harness, poor contact in the SAM or BCM unit

Advice: ring the wires, especially in the bend area (frame, connection to the trailer)

4. 🧠 Malfunctions in the body control unit (BCU / LCM)

Symptoms: failure of window lifters, wipers, mirrors, backlight

Causes: software errors, moisture, overload

Cure: MAN-cats diagnostics, replacement of the unit or software update

5. 🔧 Sensor malfunctions (ABS, ESP, AdBlue, EBS)

Frequently fail: pressure, speed, exhaust temperature sensors

Causes: open circuit, short circuit, damage to the shielded wire

Advice: check the resistance, replace the sensor or repair the wire

6. 🔋 Charging and ground problems

Symptoms: battery does not charge, "low voltage", dashboard goes out

Reasons: break in engine/cabin ground, generator overheating, bad terminals

Important: check cabin and body grounds separately (common mistake during repairs)