If a motorcycle fails to start or its electronic systems behave strangely, the problem may be because of a battery that has failed, or is in poor condition. Alternatively, the battery may be good, but electrical power may not be reaching the motorcycle’s electronics due to a faulty wiring harness or bad terminal or contact.

Test the Diagnostic Connector Voltages to determine if the motorcycle voltages are nominal with only the ignition on. The bike battery voltage as measured on the VBat pin with the engine off but the ignition on, should be above 12.3V to perform service functions safely.

Start the motorcycle’s engine while checking the VBat Level (V) value. The engine should start easily after no more than two or three seconds of cranking. The VBat Level (V) value must not drop below 9.6V after more than ten seconds of cranking. If it does, test or replace the battery.

When the engine is running, check the VBat Level (V). If the battery and alternator are in good condition, the VBat Level (V) value should stabilise at just over 14V no later than ten seconds after the engine starts. If it does not, there may be a problem with the motorcycle’s alternator or charging circuit.