Engine Controls - Trouble Shooting - No Codes: Diagnosis Infiniti M45 II

SYMPTOM DIAGNOSIS

Symptom checks cannot be used properly unless problem occurs while vehicle is being tested. To reduce diagnostic time, ensure steps in BASIC DIAGNOSTIC PROCEDURES and appropriate SELF-DIAGNOSTICS articles were performed before diagnosing a symptom. Following symptoms are available for diagnosis

1. Hard Start Or No Start (Cranks Normally)
2. Engine Stalls
3. Hesitation Or Surge
4. Spark Knock/Detonation
5. Lack Of Power/Poor Acceleration
6. High Or Low Idle
7. Rough Idle
8. Slow Return To Idle Or No Return To Idle
9. Overheats Or High Coolant Temperature
10. Excessive Fuel Consumption
11. Excessive Oil Consumption
12. Battery Dead (Under Charge)

TESTING CONDITIONS

1. Vehicle driven distance: more than 3017 miles (5000 km).
2. Barometric pressure: 14.25-15.12 psi (98.3-104.3 kPa).
3. Atmospheric temperature: 68-86°F (20-30°C).
4. Engine coolant temperature: 167-203°F (75-95°C).
5. Transmission: warmed up. After engine is warmed up to normal operating temperature, drive vehicle until FLUID TEMP SE (A/T fluid temperature sensor signal) indicates more than 140°F (60°C).
6. Electrical load: not applied (rear window defogger switch, air conditioner switch and lighting switch are in OFF position. Steering wheel in straight-ahead position).
7. Engine speed: idle.

INSPECTION PROCEDURE

Note. Perform DATA MONITOR (SPEC) mode in maximum scale display.

1. Perform BASIC INSPECTION. See «ON-VEHICLE ADJUSTMENTS»(ref-151800) article. Ensure conditions described in «TESTING CONDITIONS»(ref-151809-S07669773822003010800000) are met.
2. Select B/FUEL SCHDL, A/F ALPHA-B1 and MAS A/F SE-B1 in DATA MONITOR (SPEC) mode with CONSULT-II.
3. Compare readings on CONSULT-II screen to specifications in appropriate PID VALUE CHARTS under PIN VOLTAGE & PID VALUE CHARTS in «PIN VOLTAGE CHARTS»(ref-151811) article.
4. If readings are within specifications, system is okay at this time. If readings are not within specifications, perform «DIAGNOSTIC PROCEDURE»(ref-151809-S19656137172003010800000) .

DIAGNOSTIC PROCEDURE

For diagnostic procedure (Scheme 14)- (Scheme 16).

Scheme 14

Scheme 15

Scheme 16

PROBLEM DIAGNOSIS

Note. Perform the following procedure when problem was not found after performing testing procedure, when Diagnostic Trouble Code (DTC) cannot be verified using DTC CONFIRMATION TESTS, or when reported symptom does not recur.

1. Clear DTCs. See appropriate SELF-DIAGNOSTICS article. Inspect affected circuit ground connections by removing ground bolt or screw. Inspect all mating surfaces for rust, dirt or corrosion. Clean all mating surfaces as necessary. Reinstall bolt or screw.
2. Check for aftermarket electrical accessories which may be interfering with ground circuit. Perform «INTERMITTENT SIMULATION»(ref-151809-S07003144082003010800000) under TEST PROCEDURES.
3. The most common cause of an intermittent problem is poor electrical connections. Inspect affected harness connectors for loose connections, corrosion or loose connections.