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.
1991 Toyota Land CruiserFACTORY OEM SERVICE PROCEDURE
Knock Sensor
Probable causes of knock sensor problems include the following:
- Open or short in knock sensor circuit.
- Knock sensor (looseness etc.).
- Knock control in ECU is faulty.
Knock sensor problems can also set fault codes 52 and 53. For code charts, see TESTS W/CODES article in the ENGINE PERFORMANCE Section.
Factory Service Tools
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.