Troubleshooting-Oxygen Sensor; Manifold Absolute Pressure Sensor (Map) - Kohler ECV940 Service Manual

Troublshooting-Oxygen Sensor (O
Condition
Low voltage output.
High voltage output.
Open circuit, no activity from sensor.
Slow time response.

Manifold Absolute Pressure Sensor (MAP)

A sealed, non-serviceable assembly. A faulty sensor
must be replaced. If a blink code indicates a problem
with manifold absolute pressure sensor, it can be tested
as follows:
1. Make sure all connections are making proper
contact and are free of dirt and debris. Remove
blower housing. Slide locking tab out and pull off
manifold absolute pressure connector. Turn key
switch to ON and check with a volt meter by
contacting red lead to pin 1 and black lead to pin 2.
There should be 5 volts present, indicating ECU and
wiring harness are functioning.
62 690 05 Rev. --
)
2
Possible Cause
Shorted sensor or sensor circuit.
Shorted lead wire.
Wiring shorted to ground.
Contamination of air reference.
Air leak at sensor or gasket, sensor
upper shield damage.
Silica poisoning.
Contaminated gasoline.
Engine problem; misfi re.
Excessive rich air/fuel ratio.
Wiring shorted to voltage.
Broken element.
Sensor dropped.
Hard blow to engine or exhaust
system.
Defective sensor.
Thermal shock.
Open heater circuit.
Improper handling.
Carbon deposits.
Improper fueling.
Incorrect or contaminated fuel.
Excessive engine oil consumption
causing exhaust contamination or
other exhaust side contamination.
Heater circuit open/shorted or out of
specifi cation.
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Replace sensor or repair wiring.
Remove source of external
contamination, protect air reference
area.
Use recommended torque at
installation, replace gasket or sensor.
Revise application exhaust.
Shield sensor from damage.
Replace sensor.
Use high quality fuel.
Correct cause of misfi re.
Check for high fuel pressure
Leaking injector
Liquid fuel in vent line
Repair wiring.
Replace sensor.
Replace sensor.
Correct fueling.
Use high quality fuel.
Correct engine condition.
Repair short in harness wires, replace
sensor.
2. Check continuity in wire harness. Ohms between Pin
3 at sensor connector and Black pin 11 connector at
ECU should be near zero ohms. If no continuity is
measured or very high resistance, replace wire
harness.
3. Check to make sure intake manifold is not loose and
MAP sensor is not loose. Loose parts would allow a
vacuum leak, making MAP sensor report misleading
information to ECU.
a. Tighten all hardware and perform an ECU Reset
and a TPS Learn Procedure to see if MIL will
display a fault with MAP sensor again. If MIL fi nds
a fault with MAP sensor, replace it.
EFI SYSTEM
Conclusion
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