APRILIA RS 125 Euro 4 Service Manual page 133

RS 125 - Tuono 125 - Euro 4
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If the wiring harness is intact and the error persists, proceed with the following checks.
Short circuit to negative:
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Disconnect the sensor connector and the control unit connector.
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Check the sensor connector PIN C ground insulation. If there is no insulation, restore the
wiring harness.
•
Check the sensor connector PIN D ground insulation. If there is no insulation, restore the
wiring harness.
•
If PIN C and PIN D are insulated from the ground and the error persists, this means that
there is a probable fault in the control unit.
Lambda probe heater P0135 - shorted to positive / shorted to negative / open circuit.
Cause of error
Short-circuit to positive: excessive voltage at PIN 31 of the control unit connector.
Short circuit to negative: lack of insulation from ground on the sensor connector PIN A.
Open circuit: circuit interruption.
Troubleshooting
Short-circuit to positive:
•
Disconnect the control unit connector and the sensor connector.
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Verify that there is no short to battery positive on sensor connector PIN B (corresponding to
control unit connector PIN 31); if there is a short, restore the wiring harness.
Open circuit:
•
Disconnect the control unit connector and the sensor connector.
•
Verify continuity of the wiring harness between the sensor connector and the control unit
connector: control unit PIN 31 - sensor PIN B. If necessary, restore the wiring harness.
•
Verify continuity of the wiring harness between the sensor connector and the injection relay:
sensor PIN A - injection relay PIN 3. If necessary, restore the wiring harness.
•
If the wiring harness is intact and the error persists, proceed with the following checks.
Short circuit to negative:
•
Disconnect the sensor connector.
•
Check the sensor connector PIN B ground insulation. If there is no insulation, restore the
wiring harness.
•
If PIN B is insulated from ground and in the absence of other errors (fuel pump, injector,
coil), this means that the control unit is most likely faulty.
Injector
Function
Provide the correct amount of fuel at the correct time.
Operation / Operating principle
Electrical system
ELE SYS - 133