Iveco 01B1 – Engine Control Module (EDC / ECM) and Vehicle Control Module (VCM): Break of information CAN-line 'H'

Indicates an open circuit, interruption, or loss of communication specifically on the CAN High (CAN-H) wire of the vehicle's Controller Area Network (CAN) bus.

• Iveco Stralis
• Iveco Trakker
• Iveco Daily
• Iveco vehicles equipped with Tector, Cursor, and NEF (Tier 2) engines

1. 1

   Turn the ignition OFF. Do not measure resistance on a live CAN bus.

2. 2

   Locate the CAN pins at the diagnostic port. For standard Iveco 30-pin connectors: Pin 21 is CAN-H (White wire), Pin 22 is CAN-L (Green wire). For Stralis Euro 5 OBD (Blue) connectors: Pin 6 is CAN-H (White wire), Pin 14 is CAN-L (Green wire).

3. 3

   Measure the resistance between the CAN-H and CAN-L pins. A normal reading is ~60 Ohms. A reading of ~120 Ohms indicates a damaged or disconnected terminating resistor. A high or infinite reading confirms the CAN line is completely interrupted (open circuit). A reading of ~0 Ohms indicates a short circuit.

4. 4

   Test the continuity of the CAN-H wire (White wire) from the ECU connector to the diagnostic port to isolate the exact segment where the break occurred.

1. 1

   Disconnect Power

   Disconnect the vehicle's negative battery terminal to prevent electrical spikes during harness repair.

2. 2

   Trace the CAN-H Line

   Using the vehicle's wiring schematic, trace the CAN-H wire (identified in Iveco manuals as a White wire, often twisted with the Green CAN-L wire).

3. 3

   Inspect for Physical Damage

   Check common failure points such as harness rub-through areas along the chassis, tight bends near the engine block, and the pins at the EDC and VCM connectors. Look for backed-out pins, corrosion, or severed wires.

4. 4

   Repair the Break

   If a broken wire is found, cut out the damaged section. Splice in a new section of automotive-grade wire. Solder the connection and seal it with dual-wall adhesive heat shrink tubing to prevent moisture ingress. Ensure the CAN-H and CAN-L wires remain twisted (approximately 1 twist per inch) to prevent electromagnetic interference.

5. 5

   Verify Terminating Resistors

   If the wire is intact but the resistance was 120 Ohms, locate and test the CAN bus conclusion resistor (Iveco schematic code 61126). Replace it if it tests open.

6. 6

   Reassemble and Clear Codes

   Reconnect the battery. Use an Iveco-approved diagnostic tool (such as EASY, Texa, or Autocom) to clear the 01B1 fault code. Turn the ignition on and verify the code does not return and that module communication is restored.