Code 16: System Volt High: Notes
The ECM monitors battery voltage on circuit No. 440. If the ECM detects battery voltage greater than 16 volts for more than 10 seconds, it will set a Code 16 in memory.
NOTE:
Test numbers refer to test numbers on diagnostic chart. Starting engine with battery charger connected may set Code 16.
- Test alternator output to determine proper operation of voltage regulator. Increase engine speed to a moderate level and measure voltage across battery terminals. If reading is greater than 16 volts, service alternator.