Code 21: Barometer Sensor; Code 22: Engine Temperature Sensor - Ariens Sno-Thro Deluxe 24 Service Manual

5. Back probe the engine stator output connector. See
Figure 157.
a. Start the engine. Refer to Operator's Manual.
b. At full throttle (3600 RPM), the stator output MUST
be 11.5 – 14 volts AC.
If AC voltage measure less than 11.5 volts, remove
flywheel and replace stator.
If stator output is within range and battery is not charging,
check ECU wiring for damage. Replace ECU if necessary.
Stator
Connector
Figure 156
Figure 157

Code 21: Barometer Sensor

See Figure 152.
This trouble code indicates the barometric pressure sensor
has failed. When the barometric sensor fails, the engine will
not adjust to altitude changes, but will continue to operate
at a default altitude of 800 feet above sea level.
Engine may continue to operate with a failed barometric
pressure sensor, but may not operate at optimal
performance. If barometric pressure sensor fails, replace
ECU.

Code 22: Engine Temperature Sensor

See Figure 152.
If the sensor is damaged or has failed, the engine may not
run smoothly because the ECU cannot adjust for engine
temperature changes.
The temperature sensor and engine components can be
visually inspected for engine temperature issues:
1. Check engine cooling fan and engine cooling fins for
debris or damage.
2. Check the temperature sensor wiring from the throttle
body to the mounting boss on the side of the cylinder.
Make sure connection is secure. See Figure 158.
3. Check wiring and connection from the throttle body to
the ECU for damage.
If no damage is visible, replace throttle body assembly.
EN – 62
Temperature
Sensor
Figure 158