Function Check

TESTING PROCEDURE:

NOTE: While trouble shooting, always check the wiring, fuses and connectors for good condition and routing. Also check ground locations for good connection. Use the wiring diagrams found in SCHEMATIC DIAGRAMS to supplement your testing efforts.

Color Code Legend:

Checking ECU Ground Connections:

1. Turn ignition OFF.
2. Access fuel injection ECU by removing the passenger side kick panel and glove compartment.
3. Check fuel injection ECU ground connections. They should make good contact and fit tight.

Removing ECU Connector:

4. Remove the ECU connector by pressing up the latch and folding out the wire cluster.

Removing Protective Cover:

5. Remove connector protective sleeve.
CAUTION: ^ Never check connections from the front. Connectors can get damaged and worsen the problem.
^ Check connections through the holes in the connector.
^ Connection pin numbers are printed on the connector side.

Checking Test Points:

6. To check that the test point is not grounded, connect an ohmmeter between pin 22 (oxygen sensor system test point) and ground.

Reading: infinite

7. If not, check wiring and fix as necessary.

Checking Oxygen Sensor (Lambda Sond) Heating Element:

6. To check the oxygen sensor (lambda sond) pre-heating element, connect an ohmmeter between terminal #8 in 20-pole connector (located next to right side A-post) and ground.

a. With sensor cold (68°F or 20°C):

Reading: approx. 3 ohms

b. With sensor hot (over 660°F or 350°C which is the temperature of the sensor when the engine is hot during idle):

Reading: approx. 13 ohms

If resistance is different, check wiring from 20-pole connector to oxygen sensor (lambda sond) and from oxygen sensor to ground. Repair wiring as needed. If wiring is in good condition, replace and retest with new sensor.

Assemble Connector:

7. Disconnect the test equipment. Reconnect the ECU and all other connectors, install the kick panel and glove compartment.

Connecting CO-Meter:

8. Connect a CO-meter to the test port in the exhaust system. Use VOLVO tool #5151 or equivalent to access the test port.
9. Run engine to operating temperature.
10. Check CO content at idle.

CO should be: 0.4 - 0.8%

Disconnecting Oxygen Sensor Lead:

11. Disconnect oxygen sensor connector.

Checking ECU:

12. Ground lead to ECU.
a. The CO content should now rise, indicating correct operation of the ECU and wiring.
b. If the CO content does not rise, fault lies in the wiring or the ECU. Check wiring and repair as needed.

Reconnecting Oxygen Sensor Connector:

13. Reconnect oxygen sensor connector. Wait three (3) minutes for the adaptive system to adjust the fuel injection timing duration.

Checking Oxygen Sensor:

14. Disconnect the oxygen sensor plug and connect a voltmeter to the wire from the sensor.

The voltmeter needle should average: 0.5 volts with correct CO content (0.4 - 0.8%)

This will show that the oxygen sensor is operating correctly.
If oxygen sensor fails this test, replace and retest with new sensor.
15. Reconnect the oxygen sensor connector. Let engine run for three (3) minutes and recheck the CO content.

CO should be: 0.4 - 0.8%

16. If vehicle passes all tests and CO is not within specifications (0.4 - 0.8%), fault may be an other faulty component (injector, ECU... ).