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.
1987 Jeep Cherokee LimitedFACTORY OEM SERVICE PROCEDURE
MAT Sensor Test
- Disconnect the wire harness connector from the MAT sensor. Test the resistance of the sensor with a high impedance digital ohmmeter. The resistance should be less than 1000 ohms with the engine warm. Replace the sensor if the resistance is not within the specified range. See CTS & MAT SENSOR TEMPERATURE-TO-RESISTANCE VALUES chart.
- Test the resistance of the wire harness between the ECU wire harness connector terminal D-3 and the sensor connector terminal. Repeat the test with terminal C-8 at the ECU and the sensor connector terminal. Repair the wire harness if the resistance is greater than one ohm.
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.