Vehicle speed signal
â–¶ How to fix
Check the circuit between the tachograph and coordinator for short circuits and open circuits. Check whether the tachograph has also generated any fault codes.
What you'll see
No driver-visible symptom recorded.
System reaction
No system-reaction text recorded.
Diagnostic depth
Detection
There has been no vehicle speed signal from the tachograph.
Possible cause
The fault may be due to: Short circuit or open circuit. Internal fault in the tachograph. Poor contact or leakage currents in the circuit.