code 43

43 Fuel system voltage (monitor voltage) The ECU is unable to monitor the battery voltage (an open circuit in the line to the ECU) Fixes the battery voltage to 12 V Able Able

Thats what the code says for 43. Hope it helps.

Yamaha Error Codes for Apex, Attak, and Apex Mountain models


Code #
Item
Symptom
Fail-Safe Action Starting Capability Running Capability
11 Cylinder identification sensor No normal signals are received from the cylinder identification sensor Continues to operate the engine based on the results of the cylinder identification that existed up to that point Unable Able
12 Crankshaft position sensor No normal signals are received from the crankshaft position sensor Stops the engine (by stopping the injection and ignition) Unable Unable
13
14 Intake air pressure sensor (open or short circuit) (pipe system) Intake air pressure sensor-open or short circuit detected.
Faulty intake air pressure sensor system Fixes the intake air pressure to 85.0 kPa. Able Able
15
16 Throttle position sensor (open or short circuit) (stuck) Throttle position sensor-open or short circuit detected Fixes the throttle position sensor to fully open Able Able
20 Intake air pressure
Atmospheric pressure Defective values are detected due to the internal malfunction Fixes the intake air pressure and atmospheric pressure to 85.0 kPa. Able Able
21 Coolant temperature sensor Coolant temperature sensor-open or short circuit detected Fixes the coolant temperature to 600 C. After the engine starts, the radiator fan relay will be turned on. Able Able
22 Intake temperature sensor Intake temperature sensor-open or short circuit detected Fixes the intake temperature to 00 C. Able Able
23 Atmospheric pressure sensor (open or short circuit) Atmospheric pressure sensor-open or short circuit detected Fixes the atmospheric pressure to 85.0 kPa. Able Able
30 Oil pressure dropped Engine stops when the oil pressure drop is detected Fuel pump and fuel injection are stopped (main relay is off) Unable Unable
33
34
35
36 Faulty ignition Open circuit detected in the primary lead of the ignition coil Cut the injection of cylinder in the same group with the cylinder that the error is detected. Example, when the #1 cylinder is defective, cut the injection of #1 and #4 cylinders. Turn on the power to the air induction solenoid to always cut-off the aire Able (depending on the number of faulty cylinders) Able (depending on the number of faulty cylinders)
42 Speed sensor No normal signals are received from the speed sensor Assumes highest ratio Able Able
43 Fuel system voltage (monitor voltage) The ECU is unable to monitor the battery voltage (an open circuit in the line to the ECU) Fixes the battery voltage to 12 V Able Able
44 Error in writing the amount of CO adjustment on the EEPROM An error is detected while reading or writing on the EEPROM (CO adjustment value) n/a Able Able
46 Vehicle system power supply (monitor voltage) Power supply to the FI system is not normal Grip warmer output is off Able Able
50 ECU internal malfunction (memory check error) Faulty ECU memory. When this malfunction is detected, the code number might not appear on the meter n/a Unable Unable
80 Grip warmer switch Grip warmer switch-short circuit detected n/a Able Able
81 Grip warmer Grip warmer-open or short circuit detected n/a Able Able
82 Thumb warmer switch Thumb warmer switch-short circuit detected n/a Able Able
83 Thumb warmer Thumb warmer-short circuit detected n/a Able Able
84 T.O.R.S. Detecting conditions for T.O.R.S. are satisfied n/a Able Unable
85 Oil pressure switch Oil pressure switch-open circuit detected n/a Able Able
- Start unable warning Relay is not turned ON even if the crank signal is input while the start switch is turned ON. When the start switch is turned ON while an error is detected with the fault code of number 11, 12, 30, or 50. Engine trouble warning light flashes when the start switch is turned on Unable Unable

phazer did that last week. same code number and i thought it would be a relay too. I ended up finding that it was a bad ground. found that by un plugging the fuel pump and jumping the ground wire to a ground and plugging it back together. up under the key there should be a plug, or the one on the pump it self. all ground wires are the same color, with a small brown on blue dot on them. cant exactly remember the dot color.

Exact same thing on my T_Nytro. 4 hours of searching, testing etc. Ended up being a pin hole in my fuel pump line that was grounding out on the chasis.