Fiat Bravo Service Manual page 386

Bravo 0 * *
Copyright by Fiat Auto
LAMBDA SENSOR (0.258.003.466)
To meet the strict legislation governing the
emission of harmful residues from internal
combustion engines which require increas-
ingly more precise metering of the air/fuel
mixture, the vehicle has been equipped with
a heated Lambda sensor with four wires
which measures the oxygen content of the
exhaust gases. For a complete description of
the Lambda sensor, refer to the Fuel System
section for the 1581 16V engine.
The sensor can be rapidly put out of
action by
amounts of lead in the fuel.
Removing - ref itti ng
- Position the vehicle on a lift.
- Disconnect the negative lead from the bat-
tery.
- Disconnect the electrical connection under
the butterfly casing.
- Raise the vehicle.
- Remove the Lambda sensor from its hous-
ing.
- When tightening, do not exert force on the
component or it will be irreparably dam-
aofid.
If the Lambda sensor is being re-
placed, when refitting smear anti--
seize grease on the threaded part
(e.g. Bosch VS 14016-
Tightening torque 5 - 6 daNm
Recovery
The Lambda data is ignored (open loop) if the
sensor voltage i s > 1,099 V or between 0.400
and 0.518 V for more than 2.55 s.
Locking of self-adjustment of mixture stren-
gth for sensor voltage < 0,0879 V for more
than 2.55 s.
Open loop is considered the maximum Lam-
bda integrator value (FR) for the last good
sensor voltage reading < 0.0879 V and si-
multaneously FR=1.4.
Locking of FR at limit value reached for FR >
1.25 or < 0.75 for at least 15 s.
Wiring connector
The numbers indicate the corresponding
control unit pins.
E n g i n e
Fuel system
10.
even the slightest
FT).
3 5