Invalid speed signal or data link error
* Check the wiring and the connectors to the motions sensor and the tachograph: - Damaged wiring or connector? - Loose connector? - Poor connection? * Check the component pin assignment for the real-time motion sensor pulse signal: - Motion sensor: Pin 3 (real-time pulse output). - Tachograph: Pin B3 (real-time pulse input). - Connections between the motion sensor and the tachograph. * Check the pin assignment for the motion data signal: - Motion sensor: Pin 4 (data signal output). - Tachograph: Pin B4 (data signal input). - Connections between the motion sensor and the tachograph. * Check the motion sensor power supply: - Pin 1 voltage shall be within range: 6,5 … 9,0 V DC. Pin 2 is potential reference. * Check the motion sensor real-time speed pulse signal voltage levels: - High level shall be min: power supply from tachograph – 1,5 V. * Low level shall be max: 0,8 V. * Replace defective components * Replace the tachograph (very unlikely).
What you'll see
No driver-visible symptom recorded.
System reaction
MC22/EV302: * Warning message with error text: "sensor fault" together with Memory Code 22 is shown in the tachograph display. * The warning message will be displayed repetitively every hour until the cause is withdrawn. * Event stored in the tachograph memory * Event stored and in the inserted tachograph card. * System event in TCO1 CAN message is set to active. * Tachograph warning (amber T) is displayed in the instrument cluster. MC80: * Event warning message with error text: "motion conflict" is displayed in the tachograph display. * Event/ Fault EV302 is stored in the tachograph. * System event in TCO1 CAN message is set to active. * Tachograph warning (amber T) displayed in the instrument cluster.
Diagnostic depth
Error during sensor communication. Motion sensor pulses difference. Mismatch between received number of motion sensor real-time speed pulses and the number of speed pulses from the motion sensor data signal.
* Fault in the cable harness. * Transmission error.