Lambda Sensor Check

For this check, disconnect the plug connection in the lambda sensor wiring. The plug connections for the left and right sensors are located as follows.

Plug connections at the rear in the engine compartment:
1 – lambda sensor heater (right sensor);
2 – to ignition coil (supply wiring);
3 – lambda sensor signal (right sensor; plug connection located at the rear of the bracket);
4 – for knock sensor I;
5 – for engine speed sensor; 6 – for ignition timing sensor.

Plug connections at the rear left in the engine compartment:
1 – for lambda sensor (left lambda sensor);
2 – lambda sensor heater (left sensor);
3 – knock sensor II.

PROCEDURE

Check using a precision ohmmeter:
Special heater check: disconnect the lambda sensor heater connector.

Connect the ohmmeter to both terminals of the sensor heater cable.

Specified value for a good heater: 3—15 Ω.

Otherwise, replace the lambda sensor.

Lambda sensor check: disconnect the lambda sensor connector (calibrated wire).

Connect the ohmmeter to the connector terminals, to the sensor and to the engine block.

Specified value for a good sensor: Ω.

Otherwise, replace the lambda sensor.

Control unit line check: disconnect the lambda sensor connector (calibrated wire) (as already done).

Connect the voltmeter to the connector terminals to the control unit and to the engine block.

With good wiring, the reading should be 0.35—0.45 V.

Otherwise, check the wiring.

If the wiring is good, replace the control unit.