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Electrical system
Value drawn from the signal read without taking
into account any recovery: the value in the exam-
ple refers to an open circuit
CAUTION
BEFORE CARRYING OUT ANY TROUBLESHOOTING,
CAREFULLY READ THE GENERAL TROUBLESHOOTING
CONCEPTS FOR ELECTRICAL DEVICES AT THE BEGIN-
NING OF THE CHECK AND CONTROL SECTION IN THE
ELECTRICAL SYSTEM CHAPTER.
DIAGNOSIS INSTRUMENT: ELECTRICAL ERRORS
air temperature sensor P0110
•
open circuit, shorted to positive / shorted to negative
Error cause
•
If the circuit is open, shorted to positive: excessive voltage has been detected at PIN 37 of
the ENGINE connector. If shorted to negative: voltage equal to zero has been detected. The
instrument panel does not indicate the presence of this error even in the ATT status.
Troubleshooting
•
If the circuit is open, shorted to positive: check the sensor connector and the Marelli control
unit connector. If they are OK, check sensor continuity: replace the sensor if not OK; if OK,
check continuity between the ENGINE connector PIN 37 and the sensor PIN 1: restore cable
harness if there is not continuity; if it is OK, reconnect the control unit connector and, with
key set to key ON, check the continuity between the sensor connector PIN 2 and the vehicle
ground connection: if OK, it means that the error cause is that the cable is shorted to positive
and it is necessary to restore the cable harness between ENGINE PIN 37 and sensor PIN
1; check the sensor connector and the Marelli control unit connector. If not OK, restore the
cable harness. If OK, check continuity between the ENGINE connector PIN 6 or 17 and the
sensor connector PIN 2: restore the cable harness if there is not continuity. If there is, it
means that the control unit does not supply the ground connection and therefore should be
replaced
•
If shorted to negative, check sensor correct resistance: if resistance = 0, replace the sensor;
if resistance is correct, it means that the Purple/Black cable has ground connection: restore
the cable harness
Lambda sensor
Function
In charge of telling the control unit whether the mixture is lean or rich.
Operation / Operating principle
The Marelli injection control unit reads and interprets a voltage generated by the difference in oxygen
content between the exhaust fumes and the ambient. It does not require an external supply source but,
ELE SYS - 130
CAPONORD 1200
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