Overview:
Fault Code 34 sets Active if battery voltage to the TECU falls below 9 volts for more than 10 seconds.

Detection:
The TECU monitors the battery voltage supplied to the TECU after completing the power-up sequence. Fault Code 34 sets Active if battery voltage to the TECU falls below 9 volts for more than 10 seconds. Fault Code 33, Low Battery Voltage Supply, represents a more severe drop in battery voltage than Fault Code 34.

Conditions to Set Fault Code Active:
FMI 14 – Special Instructions: TECU monitors the battery voltage of the vehicle. If the voltage falls below 9 volts for more than 10 seconds, the fault sets Active.

Fallback:
FMI 14
• Engine may not crank.
• Transmission may not engage a gear from neutral.
• Transmission may not attempt to shift.
• Until the fault becomes Inactive, driver may have to shut off engine with transmission in gear.

Conditions to Set Fault Code Inactive:
FMI 14: Battery voltage stays at 9 volts or greater for at least 20 seconds.

Possible Causes:
FMI 14
1) Vehicle Power Supply
– Wiring shorted to ground, shorted to power or open
– Bent, spread, corroded or loose terminals
– In-line fuse corrosion, loose connection or blown fuse
2) Vehicle Batteries
– Internal failure
3) Vehicle Charging System
– Charging system failed
4) TECU
– Internal failure