Supply voltage, high
â–¶ How to fix
1. Check the battery 2. Measure the voltage level between ground and supply.
What you'll see
No driver-visible symptom recorded.
System reaction
When U30 > 30 Volt abscense of heart beat messages will not trigger warnings.
Diagnostic depth
Detection
Supply voltage above 30 Volt. Only stored when ignition is ON.
Possible cause
1. The truck is started with a booster start 2. The alternator is broken