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.
1992 Isuzu Trooper LS, StandardFACTORY OEM SERVICE PROCEDURE
Trouble Code Definition
TROUBLE CODE IDENTIFICATION
| Code | System Affected | Probable Cause | ||||
|---|---|---|---|---|---|---|
| 12 | System Normal | System Normal | ||||
| 13 | O2 Sensor | Sensor Or Circuit, ECM | ||||
| 14A (1) | Coolant Temperature Sensor | Sensor Or Circuit, ECM | ||||
| 14B (2) | Coolant Temperature Sensor | Sensor Or Circuit, ECM | ||||
| 21A | TPS Signal (High) | TPS, ECM | ||||
| 21B | TPS Signal (Low) | TPS, ECM | ||||
| 23A | MAT Circuit (Low) | Sensor Or Circuit, ECM | ||||
| 23B | MAT Circuit (High) | Sensor Or Circuit, ECM | ||||
| 24 | Vehicle Speed Sensor | Sensor Or Circuit, ECM | ||||
| 32 | EGR System | EGR Valve, Wiring Circuit, EGR Solenoid, EGR Filter, EVRV, ECM | ||||
| 33A | MAP Sensor Signal (High) | Sensor Or Circuit, ECM | ||||
| 33B | MAP Sensor Signal (Low) | Sensor Or Circuit, ECM | ||||
| 42 | Electronic Spark Timing | Wiring Circuit, Ignition Module, ECM | ||||
| 43 | Electronic Spark Control | Knock Sensor Or Circuit, ESC Module Or ECM | ||||
| 44 | O2 Sensor (Lean) | Injectors, Fuel Pressure, Exhaust Leaks, O2 Sensor or Circuit, MAP Sensor, ECM | ||||
| 45 | O2 Sensor (Rich) | Injectors, Fuel Pressure, O2 Sensor Or Circuit, MAP Sensor, TPS, Canister Purge, Ignition Shielding, ECM | ||||
| 51 | PROM Error | PROM Or ECM | ||||
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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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