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Electrical system
•
short circuit to positive/ open circuit, short circuit to negative
Error cause
•
If shorted to positive: excessive voltage has been detected at PIN 44 of the ENGINE con-
nector. If the circuit is open, shorted to negative: voltage equal to zero has been detected
at PIN 44 of the ENGINE connector. The instrument panel does not indicate the presence
of this error even in the ATT status.
Troubleshooting
•
If shorted to positive: disconnect the probe connector and check the correct resistance of
the sensor: if not OK replace the sensor; if OK restore the cable harness (black cable).
•
If circuit is open, shorted to negative: check circuit continuity from probe connector (PIN 3
and 4) toward the probe: if it is not OK, replace the probe; if it is OK, check the sensor
connector and the Marelli control unit connector: if it is not OK, restore; if it is OK, with key
set to ON and sensor connector disconnected, check if there is battery voltage at PIN 4: if
it is not OK, check the Red/Brown cable continuity between the probe connector and the
auxiliary injection relay (No. 46 in the wiring diagram, placed in the front relay box, left side;
CHECK, however, the identification of the relay with the colour of the cables). If there are
also coil, lower and upper injector and secondary air errors, check the relay and its excitation
and power line; if there is voltage at PIN 4, check the Black cable ground insulation (PIN 3):
if not OK, restore the cable harness. If it is OK, check the continuity of the Black cable
(between the sensor connector PIN 3 and the ENGINE PIN 44) and restore the cable har-
ness.
WARNING
The control unit does not detects the following malfunctions of the oxygen sensor circuit according to
the signal: interrupted circuit, shorted to ground or sensor malfunction (for example non variable volt-
age). In case of fault indication, carry out the following troubleshooting.
Injector
Injectors key:
1. Front cylinder internal injector (Marelli)
2. Rear cylinder internal injector (Marelli)
3. Front cylinder external injector (Synerject)
4. Rear cylinder external injector (Synerject)
ELE SYS - 134
CAPONORD 1200
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