Test Ego - Exhaust Gas/Oxygen Sensor

CIRCUIT PIN IDENTIFICATION

EGO Circuit	Breakout Box Pin No.	ECA Pin	Wire Color
1.8L	29	2N	Red/Blue
2.2L Non-Turbo
M/T	29	2N	Black
A/T	29	2C	Black
2.2L Turbo	29	2C	Black

NOTE: Enter this test only when a Code 15 (lean) or Code 17 (rich) is displayed during SELF-TEST procedure. This test is intended to diagnose only the EGO circuit.

1) Checking System Integrity Visually check wiring, connector and component for evidence of damage, shorting or looseness. If a fault is found, repair as necessary. If no fault is found, go to step 2).

2) Checking EGO Sensor Output Voltage Warm engine to operating temperature and let idle. Disconnect EGO sensor. Measure voltage between EGO sensor lead wire and ground. With engine at idle, voltage should be 0.2-0.8 volt.

3) Rapidly increase and decrease engine speed while reading voltmeter. When engine speed is increased, voltage should increase. When engine speed is decreased, voltage should decrease. If voltage is as specified, go to step 4). If voltage is not as specified, replace EGO sensor.

4) Isolating Open Circuit in EGO Sensor Turn ignition off. Install breakout box, leaving ECA disconnected. Disconnect EGO sensor connector. Measure continuity between EGO test pin and EGO sensor connector terminal. If continuity is present, EGO circuit is okay. If continuity is not present, repair circuit between EGO sensor and ECA.