Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2003 Infiniti M45FACTORY OEM SERVICE PROCEDURE
Data Monitor (SPEC) Mode
NOTE:
Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.
For DATA MONITOR (SPEC) mode descriptions, see DATA MONITOR (SPEC) MODE DESCRIPTIONS table.
DATA MONITOR (SPEC) MODE DESCRIPTIONS
| Monitored Item | Description |
|---|---|
| ENG SPEED [RPM] | Indicates engine speed computed from crankshaft position sensor (POS) signal. |
| MAS A/F SE-B1 [V] | The signal voltage of the mass air flow sensor specification is displayed. When engine is running, specification range is indicated. |
| B/FUEL SCHDL [msec] | "Base fuel schedule" indicates the fuel injection pulse width programmed into ECM, prior to any learned on board correction. When engine is running, specification range is indicated. |
| A/F ALPHA-B1 Or B2 [%] | The mean value of the air-fuel ratio feedback correction factor per cycle is indicated. When engine is running, specification range is indicated. This data also includes the data for the air-fuel ratio learning control. |
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.