The battery (16) can set a code when it is bad, by losing voltage during a big draw (cranking). Testing the voltage is one thing. A load test will tell you whether the battery is good or not.
You can disconnect the solenoid cable, extend it and:
The code should go away. Or I'm sure you can find someone on here with a spare exhaust actuator code (21), they get removed when you put on an aftermarket muffler so there's lots around, check the classifieds on here and BadWeb.
Codes:
Trouble Code XB Trouble Code 1125 Error Byte Error Bit (0-7) Bit Value (dec.) Meaning
11 P0122 0 5 32 TPS Voltage too low
P0123 0 6 64 TPS Voltage too high
13 P0151 0 2 4 Rear O2 Sensor always rich
P0152 0 3 8 Rear O2 Sensor always lean
P0154 0 4 16 Rear O2 Sensor inactive
14 P0117 0 0 1 Engine/Coolant Temp. Sensor Voltage too low
P0118 0 1 2 Engine/Coolant Temp. Sensor Voltage too high
15 P0112 1 6 64 Intake Air Temp. Sensor Voltage too low
P0113 1 7 128 Intake Air Temp. Sensor Voltage too high
16 P0562 1 4 16 Battery Voltage too low
P0563 1 5 32 Battery Voltage too high
21 ? 4 0 1 Exhaust Valve always open
? 4 1 2 Exhaust Valve always closed
? 4 2 4 Exhaust Valve Controller Voltage too low
? 4 3 8 Exhaust Valve Controller Voltage too high
22 P1110 1 6 64 Active Intake Controller Voltage too low
P1111 5 7 128 Active Intake Controller Voltage too high
P1112 4 4 16 Active Intake Control TPS Feedback Failure
23 P0261 1 2 4 Injector 1 (Front) Control Voltage too low
P0262 1 3 8 Injector 1 (Front) Control Voltage too high
24 P2303 2 6 64 Coil 2 (Rear) Control Voltage too low
P2304 2 7 128 Coil 2 (Rear) Control Voltage too high
25 P2301 1 0 1 Coil 1 (Front) Control Voltage too low
P2302 1 1 2 Coil 1 (Front) Control Voltage too high
26 P1154 5 4 16 Clutch Switch Voltage too low
? 5 5 32 Clutch Switch Voltage too high
27 P1155 5 2 4 Neutral Switch Voltage too low
? 5 3 8 Neutral Switch Voltage too high
32 P0264 2 4 16 Injector 2 (Rear) Control Voltage too low
P0265 2 5 32 Injector 2 (Rear) Control Voltage too high
33 P0628 2 2 4 Fuel Pump Control Voltage too low
P0629 2 3 8 Fuel Pump Control Voltage too high
34 P0506 6 5 32 Idle Air Controller Position too low (RPM too high)
P0507 6 6 64 Idle Air Controller Position too high (RPM too low)
P0511 6 7 128 Idle Air Controller Curcuit Failure
35 ? 2 0 1 Tachometer Output Voltage too low
? 2 1 2 Tachometer Output Voltage too high
36 P0691 0 7 128 Cooling Fan 1 (Rear/Right) Control Voltage too low
43 P0502 6 2 4 Vehicle Speed Sensor Input Voltage too low
P0503 6 3 8 Vehicle Speed Sensor Input Voltage too high
? 6 4 16 Vehicle Speed Output Voltage too low
44 P1151 3 6 64 Bank Angle Sensor Voltage too low
P1152 3 7 128 Bank Angle Sensor Voltage too high
46 P0616 5 0 1 Starter Relay Control Voltage too low
47 P1601 5 1 2 Auxiliary Power Relay Control Voltage too low
52 P0604 3 4 16 ECM RAM Failure
53 P0605 3 3 8 ECM ROM Failure
54 P0603 3 2 4 ECM EEPROM Failure
55 P0607 3 1 2 ECM Microprocessor Failure
54 ? 3 0 1 ECM Sync. Failure
? P1501 4 5 32 Sidestand Switch Voltage too low
P1502 4 6 64 Sidestand Switch Voltage too high
P1503 4 7 128 Sidestand Down
? P0107 8 4 16 Manifold Air Pressure Sensor Voltage too low
P0108 8 5 32 Manifold Air Pressure Sensor Voltage too high
? P2228 8 6 64 Barometric Pressure Sensor Voltage too low
P2229 8 7 128 Barometric Pressure Sensor Voltage too high
? P1047 7 4 32 O2 EGO Correction Cylinder Difference too high
57 P0192 7 2 4 Fuel Pressure Sensor Voltage too low
P0193 7 3 8 Fuel Pressure Sensor Voltage too high
P0087 7 1 2 Fuel Rail/System Pressure too low
? P0131 7 5 32 Front O2 Sensor always rich
P0132 7 6 64 Front O2 Sensor always lean
P0134 7 7 128 Front O2 Sensor inactive
? P0693 8 0 1 Cooling Fan 2 (Left) Control Voltage too low
P0694 8 1 2 Cooling Fan 2 (Left) Control Voltage too high
? P0337 8 2 4 Crank Position Sensor Voltage too low
P0338 8 3 8 Crank Position Sensor Voltage too high
? ? 10 1 2 Instrument Cluster Mode Button stuck
? ? 10 2 4 Instrument Cluster Toggle Button stuck
? ? 10 3 8 Instrument Cluster Low Fuel Light Voltage too low
? ? 10 4 16 Instrument Cluster Low Fuel Light Voltage too high
? ? 10 5 32 Instrument Cluster Communication Error
? ? 10 6 64 Instrument Cluster Oil Pressure Light Voltage Failure
? ? 10 7 128 Instrument Cluster Security Sytem Failure