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Electrical system
Indicates whether the self-acquisition process through the diagnosis instrument has/has not been car-
ried out: if it has been carried out once, will always be carried out unless EEPROM control unit zero
setting is carried out
DIAGNOSIS INSTRUMENT: ELECTRICAL ERRORS
CAUTION
IF ERRORS ARE DETECTED ON BOTH THROTTLE BODIES, CHECK ALSO THE CORRECT SUP-
PLY OF THE CONTROL UNIT TO PIN 42.
potentiometer 1 sensor, front throttle position P0120
•
short circuit to positive / open circuit, short circuit to negative
Error cause
•
If shorted to positive: excessive voltage has been detected at PIN 48. If the circuit is open,
shorted to negative: voltage equal to zero has been detected at PIN 48.
Troubleshooting
•
If shorted to positive: check the value shown by the parameter of the front throttle Potenti-
ometer 1 (voltage): disconnect the connector and read the value indicated by the diagnosis
instrument: if the voltage does not vary, there is a short circuit in the cable; replace the throttle
body if the voltage drops to zero
•
If the circuit is open, shorted to negative: check the throttle body connector and the control
unit connector. If not OK, restore; if everything is OK, check circuit continuity between the
two terminals. If not OK, restore the cable harness; if OK, check the circuit ground insulation
(from throttle sensor connector or control unit connector). If it is ground insulated, check that
there is power (+5 V) at the throttle body connector PIN 2, and that PIN 6 is connected to
ground. If both are correct, replace the throttle body
potentiometer 2 sensor, front throttle position P0122
•
short circuit to positive / open circuit, short circuit to negative
Error cause
•
If shorted to positive: excessive voltage has been detected at PIN 50. If the circuit is open,
shorted to negative: voltage equal to zero has been detected at PIN 50.
Troubleshooting
•
If shorted to positive: check the value shown by the parameter of the front throttle Potenti-
ometer 2 (voltage): disconnect the connector and read the value indicated by the diagnosis
instrument: if the voltage does not vary, there is a short circuit in the cable; replace the throttle
body if the voltage drops to zero
•
If the circuit is open, shorted to negative: check the throttle body connector and the control
unit connector. If not OK, restore; if everything is OK, check circuit continuity between the
two terminals. If not OK, restore the cable harness; if OK, check the circuit ground insulation
(from throttle sensor connector or control unit connector). If it is ground insulated, check that
ELE SYS - 148
CAPONORD 1200
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