Power supply to the tachograph
â–¶ How to fix
Check the voltage supply to the tachograph. Check the cable harness and connectors.Check whether other systems have generated a voltage supply fault code.
What you'll see
No driver-visible symptom recorded.
System reaction
No system-reaction text recorded.
Diagnostic depth
Detection
The voltage supply to the tachograph has been outside the permitted range, either above 33 V or below 8.6 V.
Possible cause
Too low a voltage can be caused by a short-circuit or open-circuit in the cable harness for the tachograph power supply. The voltage can also be too low when the engine is being started.The fault code can also be caused by the tachograph getting to high a voltage temporarily.