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Lexus Ls400 Ignition Knock (Detonation) Sensor Connectors

Lexus Ls400 Ignition knock (detonation) sensor connectors

Starting at $17.95, AutoBuffy stocks 1 ignition knock (detonation) sensor connectors from Standard Ignition for the Lexus Ls400. This connector carries the knock sensor's signal to the ECU, which retards ignition timing to prevent engine-damaging detonation. A failed or corroded connector causes the ECU to lose that signal, triggering fault codes and leaving your engine unprotected from knock.

Signs your Lexus Ls400 needs a new ignition knock sensor connector

  • Check Engine Light illuminated with stored codes P0325, P0326, P0327, P0328, P0332, or P0333 pointing to knock sensor circuit faults
  • Audible pinging, knocking, or rattling from the engine under load or acceleration, indicating timing is not being retarded properly
  • Noticeable loss of power or hesitation during acceleration as the ECU defaults to a conservative, over-retarded timing strategy
  • Reduced fuel economy because the engine cannot run at optimal ignition timing without a reliable knock sensor signal
  • Connector housing shows visible cracking, melting, or heat damage from proximity to exhaust components or the engine block
  • Connector terminals are corroded, pushed back, or making intermittent contact, causing the fault code to appear and disappear inconsistently

Which ignition knock sensor connector should you buy for your Lexus Ls400?

The most important buying decision is whether the replacement connector matches the exact terminal count, wire gauge, and locking tab design of your factory harness. Some Lexus Ls400 applications use one connector per sensor while others use two; verify your position before ordering. Material quality and weatherproofing matter here because the connector typically sits close to the engine block or exhaust heat.

OEM-equivalent pigtail connector
Best for
Owners who want a direct plug-and-play fit with no splicing guesswork
What you get
Pre-terminated pigtail with factory-matched terminals, correct wire gauge, and locking tab geometry identical to the original
Weather-sealed aftermarket connector
Best for
High-mileage or performance vehicles exposed to moisture, oil, or extreme heat
What you get
Reinforced thermoplastic housing with silicone-sealed terminal cavities that resist corrosion longer than standard connectors
Connector repair kit (terminals + housing)
Best for
DIYers who need to replace only damaged terminals inside an otherwise intact harness
What you get
Loose terminals, terminal removal tools, and a replacement housing sold together so you rebuild rather than replace the full pigtail
Dual-sensor connector set
Best for
Vehicles with two knock sensors (e.g., one per cylinder bank) where both connectors show wear
What you get
Matched pair of connectors ensuring both sensor circuits are restored simultaneously, preventing an asymmetric signal condition

Ignition knock (detonation) sensor connectors brands we stock for your Lexus Ls400

Standard Ignition
1 option · from $17.95

Replacing the ignition knock sensor connector on a Lexus Ls400

Easy⏱ 30–60 minutesTerminal removal pick or connector release toolWire stripper and crimping tool (if splicing a pigtail)Electrical contact cleanerDielectric greaseMultimeter (for post-install circuit verification)

Disconnect the battery, locate the knock sensor connector on the engine block or beneath the intake manifold, and press the locking tab to release it from the sensor. If installing a pigtail connector, splice it to the existing harness wires using heat-shrink butt connectors, matching wire colors, then apply dielectric grease to the terminals before seating the new connector. Reconnect the battery, clear any stored fault codes, and confirm with a scan tool that no knock sensor codes return after a short test drive.

Frequently asked questions

How much does it cost to replace ignition knock sensor connectors on a Lexus Ls400?
Parts start at $17.95 at AutoBuffy. The connector itself is inexpensive, but total cost depends on whether you replace only the connector or the full knock sensor as well. A shop typically bills one hour of labor for this job, so DIY replacement is a straightforward way to keep the total cost low.
Can I drive my Lexus Ls400 with a faulty knock sensor connector?
You can drive short distances, but it is not advisable. Without a valid knock sensor signal, the ECU cannot detect detonation and may either default to retarded timing — hurting power and efficiency — or allow unchecked knock, which over time causes serious internal engine damage including piston and bearing wear.
Will replacing just the connector fix my Lexus Ls400's knock sensor code?
Often yes. Knock sensor circuit codes are frequently caused by a corroded or broken connector rather than a failed sensor itself. Inspect the connector terminals for corrosion, pushed-back pins, or a broken locking tab first. If the sensor tests within specification, replacing the connector alone will resolve the fault code.
How do I tell if the knock sensor or the connector is the problem on my Lexus Ls400?
Unplug the connector and inspect terminals for green corrosion, bent pins, or moisture. Then use a multimeter to check resistance and voltage at the sensor terminals per your service manual. If the sensor reads within spec but the circuit code returns, the connector or wiring between it and the ECU is the likely culprit.
Do I need to replace the knock sensor at the same time as the connector on my Lexus Ls400?
Not automatically. If the sensor passes a resistance test and shows no physical damage, a new connector is sufficient. However, if the sensor is original and the vehicle has high mileage, or if the sensor housing is cracked or oil-contaminated, replacing both together while the area is already disassembled is practical and cost-effective.
Is the knock sensor connector on my Lexus Ls400 the same for both sensor positions?
Not always. Engines with two knock sensors — typically one per cylinder bank — may use identical connectors, but their pigtail lengths and routing differ. Always confirm the position (bank 1 or bank 2) and pigtail length when ordering to avoid a connector that reaches with difficulty or puts strain on the repaired joint.

Shop ignition knock (detonation) sensor connectors by year for the Lexus Ls400

2000199919981997199619951994199319921991

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Ignition knock (detonation) sensor connectors for other Lexus models

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