B412

Code B412 - Battery Voltage Too High:

Wiring Diagram for Codes B411 & B412:

CODE B412 - BATTERY VOLTAGE TOO HIGH

Circuit Description:

Code B412 will set when the ignition is on and the engine RPM is greater than 800 and the BCM is seeing a ignition 1 fuel reference voltage of more than 16 volts.

During the time the failure is present, the cruise control will be disengaged. When the code sets, the charging system problem page appears. This code should be fixed before trusting any other code that is set, as high voltage could cause false setting of codes.


Test Description:

1. BCM data value BD50 displays battery voltage. The normal range is between 10 and 16 volts.

2. Checks to see if the high voltage reading is due to the generator or BCM. With engine running, check voltage at the battery. If the voltage is above 16 volts the BCM is OK.

3. Checks to see if generator is faulty under load condition. If the voltage is above 16 volts refer to generator diagnosis.


Note on Intermittents:

If an intermittent Code B412 is being set, observe BCM data parameter BD50. This battery voltage reading is monitored off of the 10A ISO IGN 1 fuse fuel reference vottage, which is also used to set Code B411. If the code is being set due to a high current draw in a certain vehicle component, this can be observed by reading the display for BD50.