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.
1989 Nissan-Datsun Sentra BaseFACTORY OEM SERVICE PROCEDURE
Code Id Chart: Notes
TROUBLE CODE IDENTIFICATION CHART
| Code (1) | System Affected | Probable Cause | ||
|---|---|---|---|---|
| 11 | Crank Angle Sensor | Loss of 1° or 120/180° signal | ||
| 12 | Mass Airflow (MAF) Sensor | MAF signal high or low | ||
| 13 | Coolant Temperature Sensor | Open or shorted signal circuit | ||
| 14 | Vehicle Speed Sensor (VSS) | No VSS signal | ||
| 21 | No Ignition Reference Pulse | Loss of primary signal | ||
| 22 | Fuel Pump | Open or shorted pump circuit | ||
| 23 | Idle Switch | Open signal circuit | ||
| 25 | Idle Speed Control (AAC Valve) | Open or shorted AAC circuit | ||
| 31 | ECU | Signals are beyond normal range | ||
| 32 | EGR Sensor (Calif.) | No EGR action | ||
| 33 | Oxygen Sensor | Open circuit or high O2 signal | ||
| 35 | EGR Temperature Sensor (Calif.) | Open or shorted signal circuit | ||
| 41 | Air Temperature Sensor | Open or shorted signal circuit | ||
| 43 | Throttle Sensor | Open or shorted signal circuit | ||
| 45 | Injector Leak (Calif.) | Leak at injector | ||
| 55 | No Malfunction Recorded | Normal condition (no faults detected) | ||
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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.
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