Engine Controls - Self-Diagnostics - Testing - Q45: Other Infiniti Q45 II

Overall Function Check

Start engine and bring to normal operating temperature. Connect DVOM between PCM terminal No. 128 (PCM ground) and terminal No. 82 for right HO2S, or terminal No. 83 for left HO2S. see scheme 2 Hold engine speed at about 2000 RPM under no load. Malfunction should be detected if voltage reading remains at about.3 volt.

Start engine and bring to normal operating temperature. Connect DVOM between PCM terminal No. 128 (PCM ground) and terminal No. 82 for right HO2S, or terminal No. 83 for left HO2S. see scheme 2 Hold engine speed at about 2000 RPM under no load. Malfunction should be detected when both outputs are shifting lean, identified by maximum voltage reading is less than.6 volt and minimum voltage reading is less than.1 volt.

Start engine and bring to normal operating temperature. Connect DVOM between PCM terminal No. 128 (PCM ground) and terminal No. 82 for right HO2S, or terminal No. 83 for left HO2S. see scheme 2 Hold engine speed at about 2000 RPM under no load. Malfunction should be detected when both outputs are shifting rich, identified by maximum voltage reading is more than.8 volt and minimum voltage reading is more than.35 volt.

Start engine and bring to normal operating temperature. Connect DVOM between PCM terminal No. 128 (PCM ground) and terminal No. 82 for right HO2S, or terminal No. 83 for left HO2S. see scheme 2 Hold engine speed at about 2000 RPM under no load. Malfunction should be detected if vehicle does not enter into closed loop operation. See FUEL FEEDBACK MONITORING USING MIL under ADDITIONAL SYSTEM FEATURES in TESTS W/CODES - INTRODUCTION article.

Start engine and bring to normal operating temperature. Connect a DVOM between PCM terminal No. 128 (PCM ground) and No. 89 (White wire) for left rear HO2S, or terminal No. 90 (Yellow wire) for right rear HO2S. see scheme 2 Check voltage reading while revving engine up to 4000 RPM under no load at least 10 times. Reading should be less than.54 volt at least once. If reading is not less than.54 volt at least once, allow vehicle to idle for 10 minutes and retest, or test drive vehicle and check reading while coasting from 50 MPH. If reading is less than.54 volt, system is okay at this time. If reading is not less than.54 volt at least once, go to DIAGNOSTIC PROCEDURE.

Start engine and bring to normal operating temperature. Connect a DVOM between PCM terminal No. 128 and No. 89 (White wire) for right rear HO2S, or No. 90 (Yellow wire) for left rear HO2S. see scheme 2 Check voltage reading while revving engine up to 4000 RPM under no load at least 10 times. Reading should be greater than.56 volt at least once. If reading is not greater than.56 volt at least once, allow vehicle to idle for 10 minutes and retest, or test drive vehicle and check reading while coasting from 50 MPH. If reading is greater than.56 volt at least once, system is okay at this time. If reading is not greater than.56 volt at least once, go to DIAGNOSTIC PROCEDURE.

Start engine and bring to normal operating temperature. Connect a DVOM between PCM terminal No. 128 and No. 89 (White wire) for right rear HO2S, No. 90 (Yellow wire) for left rear HO2S. see scheme 2 Check voltage reading while revving engine up to 4000 RPM under no load at least 10 times. Reading should changed more than.06 volt for a one second. If reading does not change more.06 volt for one second, allow vehicle to idle for 10 minutes and retest, or test drive vehicle and check reading while coasting from 50 MPH. If reading change is greater than.06 volt for one second, system is okay at this time. If reading does not change more than.06 volt for one second, go to DIAGNOSTIC PROCEDURE.

Start engine and bring to normal operating temperature. Using DVOM, backprobe PCM terminal No. 128 and No. 89 (White wire) for right HO2S, or terminal No. 90 (Yellow wire) for left HO2S. see scheme 2 Check voltage while racing up to 4000 RPM, under no load at least 10 times. If voltage reading remains less than 2 volts, system is okay at this time. If voltage reading is greater than 2 volts, go to DIAGNOSTIC PROCEDURE.

DTC is set when low EGR flow is detected during specific driving conditions. Raise and support vehicle drive wheels. Start engine, turn TCS switch to OFF position, and bring to normal operating temperature. Place shift lever into "D" position. Check EGR valve lift when revving from idle to about 3000 RPM. EGR valve should lift up and return down smoothly, without sticking or binding.

Backprobe between ground and EGR temperature sensor harness connector White wire terminal at idle. Reading should be less than 4.5 volts. Turn ignition off. Disconnect EGR temperature sensor and PCM connectors. Check continuity between EGR temperature sensor connector Black wire terminal and PCM connector terminal No. 129. Continuity should exist. If readings are not as specified, DTC should be set.

Check Component

Ensure vacuum hoses are routed correctly. (Scheme 53) Inspect EGRC-BPT valve and EGR system. See I - SYSTEM & COMPONENT TESTS article. Repair or replace as required and perform final check. See FINAL CHECK under SELF-DIAGNOSTIC SYSTEM in TESTS W/CODES - INTRODUCTION article.

Scheme 53

Overall Functional Check

Raise and support drive wheels. Start engine. Place TCS switch in OFF position. Place selector lever in Drive. Using a DVOM connected to ground, read voltage at PCM connector terminal No. 68 (Pink/Blue wire). Voltage reading should be about 2.5 volts, indicating voltage switching (0-5). If reading is not correct, DTC should be set. It may be necessary to repeat this procedure for DTC to set.

1. Check Speedometer Operation - Raise and support drive wheels. Start engine. With transaxle in gear, check speedometer operation. If speedometer operation is okay, go to next step. If speedometer operation is faulty, check Yellow and Yellow/Blue wire circuits between VSS and combination meter. Repair as necessary.
2. Check Input Signal Circuit - Turn ignition off. Disconnect PCM harness connector and combination meter harness connector. Check harness continuity between PCM terminal No. 29 and combination meter terminal No. 16 (Pink/Blue wire). (Scheme 54) If continuity is present, go to next step. If continuity is not present, repair harness or connectors as necessary and perform final check. See FINAL CHECK under SELF-DIAGNOSTIC SYSTEM in «TESTS W/CODES - INTRODUCTION»(ref-18059) article.
3. Check Component - Remove VSS from transaxle. Using a DVOM, check resistance between VSS connector terminals. Resistance should be about 250 ohms. Set DVOM on AC scale. Connect DVOM to VSS connector terminals. Quickly turn VSS pinion gear. Voltage generated should be about 0.5 volt.
4. If resistance and voltage are not correct, replace vehicle speed sensor. If resistance and voltage are correct, disconnect system harness connectors and inspect for damage or corrosion. Repair as necessary and retest.

Scheme 54

Start engine and bring to normal operating temperature. Check voltage between ground and PCM terminal No. 74 (Gray/Blue wire). At idle, battery voltage should be present. Increase engine speed to 2000 RPM, about zero volts should be present. If readings are not as specified, DTC should set. Go to DIAGNOSTIC PROCEDURE.