Locating and Repairing Knock Sensor Wiring Damage (Toyota Prado 150 Series Petrol)

Toyota Prado 150 Series
1

Introduction

This article outlines the process of locating and repairing damaged knock sensor wiring in a 2010 Toyota Prado 150 series petrol engine, specifically damage caused by rodents. The procedure involves accessing the sensors, identifying the damage, repairing the wiring, and clearing error codes.

Problem

The vehicle exhibited a flashing 4WD light, VSC light, and engine light, diagnosed by a Toyota dealer as a knock sensor error. Rodent activity was suspected as the cause of the wiring damage.

Solution

The solution involved locating the knock sensors, repairing the damaged wiring, and clearing the error codes.

  1. Locate the Knock Sensors: The vehicle has two knock sensors, one on each bank of the engine. They are located in a difficult-to-access area under the air plenum chamber.
  2. Access the Sensors:
    • Remove the black air plenum chamber on top of the engine.
    • Disconnect numerous rubber hoses and sensor plugs.
    • Remove the valley cover.
    • Ensure all intake ports are covered to prevent debris from entering.
  3. Identify the Damage: The knock sensor is a round component with wiring connected to it. Inspect the wiring for signs of rodent damage (chewed or severed wires). In this case, the wires were chewed back to the main wiring loom.
  4. Wiring Repair:
    • Carefully disassemble the plug connecting to the knock sensor.
    • Attach new high-temperature wires to the plug.
    • Unwrap approximately 40mm of the main wiring loom to expose enough wire for repair.
    • Solder, crimp, and heat shrink the new wires from the plug to the existing wiring in the loom.
  5. Clear Error Codes:
    • Disconnect the positive battery terminal.
    • Bridge the positive lead to earth (chassis ground) to clear error logs.
    • Reconnect the positive battery terminal.
    • Start the engine to confirm the issue is resolved.

Relevant Parts

  • High-temperature automotive wire
  • Solder
  • Crimp connectors
  • Heat shrink tubing

This technical summary was auto-generated based on recovered archives. Do not rely on its factual accuracy. Refer to the original thread. Source: View Original Conversation

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