EN – 66
Code 21: Barometer Sensor
See Figure 147.
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 147.
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 156.
3.
Check wiring and connection from the throttle body to
the ECU for damage.
If no damage is visible, replace throttle body assembly.
Code 23: EFI System Cannot Sustain
Desired RPM
The ECU reads the RPM through the alternator. If a faulty
connection exists, the ECU will not read the RPM correctly.
1.
Start engine.
2.
Check AC voltage of the alternator by back probing
the wire harness connector at the engine. Voltage
should read 11.5 V AC – 14 V AC. If voltage is within
specification record the voltage and move to step 3.
a. If voltage is not to specification, inspect wires to
connectors. If wires are disconnected, repair or
replace wire harness.
b. If connections are in good condition, disconnect
and reconnect wire harness and recheck voltage.
Voltage should read 11.5 V AC – 14 V AC.
c. If low or no voltage exists, remove the flywheel
and inspect the alternator ground wire contact. If
ground wire is corroded, repair alternator. If
ground contact is in good condition, replace
alternator.
3.
Check voltage of the black and gray wires to the
14-pin connector at the ECU. Record the voltage here
and compare to reading from step 2.
a. If voltage drop of 1 V AC or greater is observed,
inspect wire connections for a disconnected or
corroded connection. If wires are disconnected or
corroded, repair or replace wire harness.
b. If connections are in good condition, disconnect
and reconnect harness and recheck for voltage
drop. Voltage should read 11.5 V AC – 14 V AC.
c. If voltage drop of 1.0 V AC or higher is still
present, replace wire harness(es).
4.
If voltage is within specification and less than 1 VDC
voltage drop from alternator to ECU, and trouble code
still appears or the engine is still not performing
optimally, replace ECU.
Code 27: Low Fuel Pressure
Low fuel pressure is usually a result of an empty fuel tank,
but could also be from a clogged fuel filter or faulty fuel
pump.
Attempt engine start and check for trouble code re-
occurrence after each of the following steps. Refer to
Operator’s Manual for engine starting instructions.
1.
Check fuel level and fill fuel tank completely if not
already full.
2.
Check fuel lines to ensure there are no leaks or kinks.
3.
Check inline fuel filter for debris and blockage. See
Figure 157.
Figure 156
Temperature
Sensor
CAUTION:
AVOID INJURY. Fuel lines are
pressurized; wear safety glasses.
