Lambda sensor
Function
In charge of telling the control unit whether the
mixture is lean or rich.
Operation / Operating principle
Based on the difference of oxygen in the exhaust
fumes and the environment, this generates volt-
age which is read and interpreted by the injection
control unit. It does not require an external supply
source but, in order to work properly, it should
reach a high operating temperature: that is why
there is a heating circuit inside.
Pin-out:
1. Heater power (A)
2. Heater ground (B)
3. Sensor (C)
4. Sensor signal - (D)
CAUTION
BEFORE CARRYING OUT ANY TROUBLESHOOTING, CAREFULLY READ THE GENERAL TROU-
BLESHOOTING CONCEPTS FOR ELECTRICAL DEVICES AT THE BEGINNING OF THE CHECK
AND CONTROL SECTION IN THE ELECTRICAL SYSTEM CHAPTER.
ELECTRICAL ERRORS
Check the air-fuel ratio / Lambda probe P0130
- short to positive / open circuit, short to negative or
carburetion excessively lean / signal not plausible for abnormal title correction or probe signal fault.
Error cause
Shorted to positive: excessive voltage at PIN 11 or PIN 12 of the control unit connector.
Circuit open or shorted to negative: interruption of the circuit or null voltage between control unit con-
nector PIN 11 and 12.
Troubleshooting
Shorted to positive:
•
Disconnect the control unit connector and the sensor connector.
•
Verify that there is no short to battery positive on sensor connector PIN C (corresponding
to control unit connector PIN 11); if there is a short, restore the cabling.
•
Verify that there is no short to battery positive on sensor connector PIN D (corresponding
to control unit connector PIN 12); if there is a short, restore the cabling.
The circuit is open:
•
Disconnect the control unit connector and the sensor connector.
RS4 125
Electrical system
ELE SYS - 117
Summary of Contents for RS4 125
Page 1: ...SERVICE STATION MANUAL B043126 RS4 125 ...
Page 5: ...INDEX OF TOPICS CHARACTERISTICS CHAR ...
Page 44: ...INDEX OF TOPICS SPECIAL TOOLS S TOOLS ...
Page 49: ...INDEX OF TOPICS MAINTENANCE MAIN ...
Page 63: ...INDEX OF TOPICS ELECTRICAL SYSTEM ELE SYS ...
Page 126: ...INDEX OF TOPICS ENGINE FROM VEHICLE ENG VE ...
Page 139: ...INDEX OF TOPICS ENGINE ENG ...
Page 146: ... Remove the oil filter Engine RS4 125 ENG 146 ...
Page 198: ...INDEX OF TOPICS POWER SUPPLY P SUPP ...
Page 203: ... Loosen the clamp and remove the throttle body RS4 125 Power supply P SUPP 203 ...
Page 204: ...INDEX OF TOPICS SUSPENSIONS SUSP ...
Page 230: ...INDEX OF TOPICS CHASSIS CHAS ...
Page 247: ...INDEX OF TOPICS BRAKING SYSTEM BRAK SYS ...
Page 262: ...INDEX OF TOPICS COOLING SYSTEM COOL SYS ...
Page 273: ...INDEX OF TOPICS BODYWORK BODYW ...
Page 290: ...INDEX OF TOPICS PRE DELIVERY PRE DE ...
Page 298: ...Windshield Wiring diagram 92 ...