APRILIA SHIVER 900 Service Station Manual page 166

Electrical system
•
Performed/Not performed
Indicates if the self-learning with the diagnostic tool was performed/not performed: if it was performed
one time, it will always remain performed unless a control unit EEPROM reset is carried out
DIAGNOSTIC TOOL: ELECTRICAL ERRORS
CAUTION
IF ERRORS ARE DETECTED ON BOTH THROTTLE BODIES, CHECK ALSO THE CORRECT SUP-
PLY OF THE CONTROL UNIT TO PIN 42.
P0120 Front throttle valve position potentiometer sensor
Electrical diagnosis:
•
short circuit to positive / open circuit, short circuit to negative
Error cause:
•
Short-circuit to positive: excessive voltage has been detected on PIN 48. If open circuit, short
circuit to negative: voltage equal to zero detected at PIN 48.
Troubleshooting:
•
Short-circuit to positive: check the value indicated by the Potentiometer 1 front Throttle valve
parameter (voltage): disconnect the connector and read the value indicated in the diagnostic
tool: if the voltage does not vary, there is a short circuit in the concerned cable; replace the
throttle body if the voltage drops to zero
•
If open circuit, short circuit to negative: perform the check procedure for the throttle body
connector and control unit connector; if not ok, restore, if everything is ok, check the con-
tinuity of the circuit between the two ends; if not ok, restore the wiring harness, if ok, check
the ground insulation of the circuit (from the throttle body connector or control unit connec-
tor); if ground insulated, check that at PIN 2of the throttle boy connector there is power supply
(+5 V) and that at PIN 6 there is ground; if they are correct, replace the throttle body.
P2120 Rear throttle valve position potentiometer 1 sensor
Electrical diagnosis:
•
short circuit to positive / open circuit, short circuit to negative
Error cause:
•
Short-circuit to positive: excessive voltage has been detected on PIN 36. If open circuit, short
circuit to negative: voltage equal to zero detected at PIN 36.
Troubleshooting:
•
Short-circuit to positive: check the value indicated by the Potentiometer 1 rear Throttle valve
parameter (voltage): disconnect the connector and read the value indicated in the diagnostic
tool: if the voltage does not vary, there is a short circuit in the concerned cable; replace the
throttle body if the voltage drops to zero
•
If open circuit, short circuit to negative: perform the check procedure for the throttle body
connector and control unit connector; if not ok, restore, if everything is ok, check the con-
ELE SYS - 166
SHIVER 900