Engine Controls - System/component Tests: Diagnosis Toyota Paseo L40

Oxygen Sensor Feedback Voltage Test

1. Warm engine to normal operating temperature. Connect analog voltmeter to terminals VF1 and E1 of Data Link Connector No. 1 (DLC1). (Scheme 40) Perform test procedures listed. (Scheme 41)and (Scheme 42).
2. Depending on model application, some vehicles may be equipped with a main oxygen sensor, sub-oxygen sensor and a sensor heater. See «OXYGEN SENSOR APPLICATION»(ref-21199-S34723254942001010300000) table.

Note. Diagnostic trouble Codes 21, 25, 26, 27 and 28 (some models) are oxygen sensor circuit codes. For trouble code charts, see G - TESTS W/CODES article.

OXYGEN SENSOR APPLICATION

Scheme 40

Scheme 41

Scheme 42

Pick-Up Coils

See PICK-UP COIL AIR GAP and PICK-UP COIL RESISTANCE under IGNITION CHECKS in BASIC TESTING article.

EGR System Test

1. Ensure EGR vacuum modulator filter(s) are clean and in good condition. Clean filter(s) with compressed air (if necessary).
2. Using "T" connector, install vacuum gauge in vacuum line to EGR valve. Start engine. Ensure engine runs idles smoothly to ensure proper seating of EGR valve. NOTE: The EGR system components can be checked with engine coolant temperature less than minimum temperature and engine at specified engine RPM.
3. Operate engine with engine coolant temperature less than minimum temperature and at specified RPM. See «EGR TESTING SPECIFICATIONS»(ref-21199-S03335561862001010300000) table. No vacuum reading should be obtained.
4. Warm engine to normal operating temperature. Operate engine at specified engine RPM again. See «EGR TESTING SPECIFICATIONS»(ref-21199-S03335561862001010300000) table. Ensure a low vacuum reading is now obtained.
5. Disconnect vacuum hose from port "R" of EGR vacuum modulator. (Scheme 43)
6. Using additional hose, connect port "R" of EGR vacuum modulator directly to intake manifold. High vacuum reading should be obtained at specified engine RPM. See «EGR TESTING SPECIFICATIONS»(ref-21199-S03335561862001010300000) table. NOTE: Engine should misfire due to large amounts of exhaust gas being injected into intake manifold.
7. Remove vacuum hose and reconnect original vacuum hose to EGR vacuum modulator.
8. To check EGR valve operation, remove vacuum hose from EGR valve. Using vacuum pump, apply vacuum directly to EGR valve with engine idling. Engine should run rough or stall. If EGR system does not operate as described, each individual component should be tested.

Scheme 43

EGR TESTING SPECIFICATIONS