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.
Diagnostic Modes
The self-diagnostic system can detect ECCS malfunctions and store related trouble code. Trouble codes, including intermittent codes, are stored in ECU memory and are available for interpretation unless codes have been cleared.
A dual Light Emitting Diodes (LED), located on the ECU is used. For system application, see SELF-DIAGNOSTIC SYSTEM table. On Pulsar and Sentra 2WD models, the ECU is located between the front seats. On Sentra 4WD models, the ECU is located under driver seat.
| Application | CHECK ENGINE Light | LED COLORS (No.) |
|---|---|---|
| Pulsar NX, Sentra | Calif | Red & Green (2) |
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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.