Code 11: Heated Oxygen Sensor (Ho2S) (4-Wire Oxygen Sensor)

NOTE: For component terminal identification, see TERMINAL IDENTIFICATION . For wiring diagrams, see WIRING DIAGRAMS article in the ENGINE PERFORMANCE Section.

NOTE: In the following steps, the first terminal listed is positive. The second terminal listed is negative.

If using scan tester, go to step 3). Disconnect HO2S connector. Install Test Harness (MB998464 ) between HO2S and HO2S connector. Use DVOM to check resistance between specified HO2S connector heater terminals. See HO2S CONNECTOR TERMINAL LOCATION table. HO2S resistance should be 20 ohms at 68°F (20°C). If resistance is not as specified, replace HO2S. If resistance is as specified, go to next step.

HO2S CONNECTOR TERMINAL LOCATION

Application

⁽¹⁾ Heater Terminals No.

Output Terminals No.

Eclipse 2.0L

3 & 4

1 & 2

⁽¹⁾

First terminal listed is positive. Second terminal listed is negative.

Using jumper wires, apply 12 volts to HO2S connector heater terminals No. 3 & 4 (2.0L). Using DVOM, check voltage between HO2S connector output terminals No. 1 & 2 (2.0L), while repeatedly racing engine. If voltage is not .6-1.0 volt, replace HO2S. If voltage is .6-1.0 volt, go to step 5).
Start and warm engine to operating temperature. Using scan tester, read HO2S voltage. While monitoring scan tester, accelerate to 4000 RPM. Suddenly decelerate. Scan tester should read .3 volt or less. Suddenly accelerate. Scan tester should read .5-1.0 volt. If voltage is not as specified, replace HO2S. If voltage is as specified, go to next step.
While monitoring scan tester, accelerate to 2000 RPM and decelerate to 700 RPM (idle). Scan tester should switch between .6-1.0 volt and .4 volt or less. If voltage is not as specified, replace HO2S. If voltage is as specified, go to next step.
Disconnect HO2S connector. Go to next step.
Turn ignition switch to ON position. Using DVOM, check voltage between HO2S connector terminal No. 3 and chassis ground. If system voltage does not exist, repair wiring harness as necessary. If system voltage exists, go to next step.
Using DVOM, check for continuity between HO2S connector terminal No. 1 (2.0L) and ECM connector terminal No. 4 (2.0L). If continuity does not exist on either circuit, repair appropriate circuit for open or short to ground as necessary. If continuity exists, go to next step.
Disconnect HO2S connector. Using DVOM, check for continuity between HO2S connector terminal No. 4 and chassis ground. If continuity does not exist, repair wiring harness as necessary. If no system or component malfunctions occur in preceding tests, condition required to set trouble code is not present at this time. Test is complete. Intermittent problem may exist. See TESTS W/O CODES article in the ENGINE PERFORMANCE Section.