Ignition switch "OFF"
Disconnect battery (-) cable.
Refer to "Shop Manual" and disconnect upstream lambda sensor unit connector.
Measure the resistance between Pin No. 2 (Heater Power) terminal and Pin No. 5 (Heater Control) terminal of upstream lambda sensor unit.
Specification : Approx. 2.4 - 4.0Ω (Approx. 20℃)
Is the measured value within specification?
 | ▶ Go to "Visual Inspection" procedure. |
 | ▶ Carefully re-do this troubleshooting guide steps. ▶ If no problems were found with the circuits or connectors, replace the upstream lambda sensor unit and go to "Verification of Vehicle Repair" procedure. |
Ignition switch "OFF"
Disconnect battery (-) cable.
Refer to "Shop Manual" and remove lambda sensor unit.
Refer to "Shop Manual" and inspect for following conditions:
- Corrosion and water influx in terminal
- Damaged wiring protection tube, and open in wiring
- Proper installation of the sensor
- Damaged, deformed, or melted sensing element of the sensor
Are the result of the inspection items normal?
| ▶ Fault is intermittent caused by poor contact in the sensor’s and/or ECM’s connector or was repaired and ECM memory was not cleared. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of vehicle Repair" procedure. |
| ▶ Carefully re-do this troubleshooting guide steps. ▶ If no problems were found with the circuits or connectors, replace the upstream lambda sensor unit and go to "Verification of Vehicle Repair" procedure. |
When installing component, tighten it within specification.
If component is dropped, check for proper operation. The internal damage may be present.
Do not use cleaner, spray or grease. It may affect performance of lambda sensor.
Wiring of lambda sensor may be damaged from direct contact on exhaust manifold or other exhaust system.
When lambda sensor is replaced, perform "Essential work after component replacement. Otherwise, vehicle performance and emission control may not work properly until auto learning is completed.
Ignition switch "OFF"
Connect GDS to Data Link Connector (DLC).
Ignition switch "ON" & Engine "OFF"
Perform "Essential Work After Component Replacement" in "Vehicle S/W Management" with GDS.
Select "Lambda Sensor(LSU) Change"
Fig.1) Vehicle S/W Management list of U2 engine
Fig.2) "Essential Work After Component Replacement"
Fig.3) Lambda Sensor(LSU) Change
Fig.4) Complete
