Cagiva Navigator, Workshop Manual, Page: 78 / 407

C.34
INJECTION - AIR INTAKE SYSTEM
“C13” SENSOR CIRCUIT MALFUNCTION
PROBLEM POSSIBLE CAUSE
Low voltage and pressure.
High voltage and pressure.
(0,5V Sensor voltage < 4,5V)
Outside the indicated range.
NOTE:
Note that the atmospheric pressure varies accord-
ing to weather conditions and the altitude.
Take into consideration these factors when check-
ing the voltage.
• Suction passageway between the carburettor and the
IAP sensor blocked.
• Air taken in from the suction passageway between the
carburettor and the IAP sensor.
• Red/orange lead circuit open or in short-circuit to Earth.
• Black/brown or yellow/grey lead circuit in short-circuit
to Earth.
• IAP sensor malfunction.
• ECM malfunction.
…
…
CHECK
• Remove the seat.
• Disassemble the left hand fuel tank as described in Chapter B.
1 Turn the ignition switch to the OFF position.
Check to see if the connector contacts of the IAP sensor are
loose or ruined.
If OK, measure the incoming voltage of the IAP sensor.
Disconnect the connector of the IAP sensor.
Turn the ignition switch to the ON position.
Measure the voltage between the red/orange lead and Earth.
If OK, measure the voltage between the red/orange lead and
the black/brown lead.
IAP sensor incoming voltage. 4.5-5.5V
(Red/orange –Earth)
(Red/orange –black/brown)
Tester dial indication: Voltage ( — )
NO ECM connector contacts loose or
ruined. Open circuit or short-circuit of
YES the red lead or the black/brown lead.
2 Connect the IAP sensor connector.
Switch on the engine and let it run on tickover.
Measure the outgoing voltage of the IAP sensor on the
connector between the yellow/grey lead and the black/brown lead.
IAP sensor outgoing voltage: approx. 1.8V at minimum
(yellow/grey –black/brown)
Tester dial indication: Voltage ( — )
Check to see if the suction tube is
NO cracked or damaged.
Yellow/grey lead circuit open or in
short-circuit.
YES Substitute the IAP sensor.
Rosso
Red/
Orange
Black/Brown
Nero/Marrone
Giallo/Grigio
Red/
Orange