DTC 11

System Schematic:

To test the Oxygen Sensor, located on the exhaust manifold, proceed as follows.

1. Disconnect the oxygen sensor connector and connect a digital voltmeter to the sensor connector.
2. Warm the engine until the coolant temperature exceeds 80~C (176~F).
3. Measure the sensor output while repeatedly racing the engine. Sensor voltage should be within .6v - 1.0v, due to the rich condition created by racing the engine repeatedly. If there is no reading or inaccurate readings, the sensor may be bad or there could be a fuel mixture problem. Refer to DIAGNOSIS BY SYMPTOM for further system troubleshooting.


OSCILLOSCOPE TEST

Osciloscope Test:

1. Connect scope pickup probe to the sensor terminal 1.
2. Warm engine to operating temperature and keep it running at 2,000 RPM, check the waveform on the scope.
If scope pattern is not as depicted in image, continue with the rest of the test procedures before replacing the assembly.

HARNESS TEST

1. Disconnect the oxygen sensor and the ECU connector.

2. Using an Ohmmeter, check for continuity (short) to ground between the ECU harness connector terminal 4 and the oxygen sensor harness connector terminal 1.

Continuity: Should Not Exist.

3. Using an Ohmmeter, check for continuity between the ECU harness connector terminal 4 and the oxygen sensor harness connector terminal 1.

Continuity: Should Not Exist.


4. Check for continuity of the ground circuit between the harness connector terminal 2 and ground.

Continuity: Should Exist.


If any of the previous tests produce unsatisfactory results, the harness will need to be repaired or replaced. Once repairs have been completed, clear the trouble codes and road test the vehicle to confirm that the repair has corrected the problem and the code doesn't return.

If the same trouble code reoccurs, it is possible that there is an intermittent failure of the component or the ECU. Check for looseness at all harness junctions and test for an intermittent failure.