4.6
9940259 R02 - 2022
RZR
PRO R / PRO R 4 Service Manual
© Copyright Polaris Industries Inc.
CRANKSHAFT POSITION SENSOR (CPS)
CPS OPERATION OVERVIEW
Mounted below the starter, the crankshaft position
sensor
q
is essential to engine operation, constantly
monitoring the rotational speed (RPM) and position of the
crankshaft.
A ferromagnetic 35-tooth encoder ring with a missing
tooth is built onto the flywheel. The inductive speed
sensor is mounted 1.0 ± 0.26 mm (0.059 ± 0.010 in.)
away from the encoder ring. During rotation, an AC pulse
is created within the sensor for each passing tooth. The
ECU calculates engine speed from the time interval
between the consecutive pulses.
The encoder ring missing tooth creates an “interrupt”
input signal, corresponding to specific crankshaft
position. This signal serves as a reference for the control
of ignition timing by the ECU. Synchronization of the
CPS and crankshaft position takes place during the first
two revolutions each time the engine is started. This
sensor must be properly connected at all times. If the
sensor fails or becomes disconnected for any reason, the
engine will stop running.
CPS TEST
The CPS is a sealed, non-serviceable assembly. If fault
code diagnosis indicates a problem with this sensor, test
as follows:
1.
Locate the CPS harness connector above the
transmission on the RH side of the vehicle and
disconnect the harness.
2.
Pin
q
is for the shield circuit and it should be OL to
pins
w
&
e
. A resistance reading would indicate a
shorted sensor.
3.
Connect an ohmmeter between CPS pin terminals
w
&
e
. A resistance value of
1000Ω ± 10%
at room
temperature should be obtained.
CPS Resistance Specification:
1000Ω ± 10%
4.
If the resistance is correct:
• Test the main harness circuit between the sensor
connector terminals and the corresponding pin
terminals at the ECU (see wiring diagram).
• Check the sensor mounting, air gap, flywheel encoder
ring for damage or runout, and flywheel key. Follow the
CPS Replacement procedure to inspect CPS and
flywheel encoder ring for damage.
5.
If the resistance is incorrect, follow the CPS
Replacement page
procedure.
