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Lexus Lx470 Transmission Control Relays

Lexus Lx470 Transmission control relays

Starting at $606.95, AutoBuffy stocks 1 transmission control relays from Standard Ignition to fit your Lexus Lx470. The transmission control relay supplies switched power to the transmission control module (TCM) and solenoid circuits — when it fails, the TCM loses power or receives intermittent voltage, triggering limp mode, shift faults, and potential no-start conditions.

Signs your Lexus Lx470 needs a new transmission control relay

  • Transmission stuck in limp mode — locked in a single gear regardless of selector position
  • No-crank or no-start condition caused by the relay's involvement in the PCM/TCM power feed circuit
  • Check Engine or transmission warning light with shift-solenoid or TCM power-supply fault codes stored
  • Harsh, delayed, or erratic shifts that appear suddenly rather than gradually worsening
  • Transmission fails to engage Drive or Reverse after the vehicle sits overnight in cold weather
  • Relay clicks or chatters audibly in the fuse box under the dash or hood when the ignition is cycled

Which transmission control relay should you buy for your Lexus Lx470?

Transmission control relays are standardized mini ISO relays, but load rating, contact material, and whether you need a single relay or a fuse-relay module assembly all affect fitment and longevity. Match the relay's amperage rating and terminal configuration to the original — substituting a lower-rated relay is a common cause of repeat failure.

OE-equivalent relay (standalone)
Best for
Daily drivers wanting a direct drop-in fix
What you get
Correct amperage rating, terminal pitch, and coil resistance for the Lexus Lx470's fuse/relay box
Heavy-duty or upgraded relay
Best for
High-mileage vehicles or those with a history of electrical heat soak
What you get
Silver-alloy contacts and a higher continuous current rating for longer service life
Fuse and relay box assembly
Best for
Lexus Lx470 builds where corrosion or burn damage has spread to the relay box itself
What you get
Complete pre-assembled unit that replaces the housing, terminals, and relay together — eliminates terminal rework
OEM-brand relay
Best for
Owners who want factory specification and full compatibility assurance
What you get
Manufactured to the original equipment specification, typically with matching part coding for the Lexus Lx470's TCM circuit

Transmission control relays brands we stock for your Lexus Lx470

Standard Ignition
1 option · from $606.95

Replacing the transmission control relay on a Lexus Lx470

Easy⏱ 15–30 minutesRelay puller or small flathead screwdriverMultimeterOBD-II scan tool (for clearing fault codes)Fuse box diagram (owner's manual or underhood label)

Locate the transmission control relay in the fuse/relay box using the diagram on the box cover or in the owner's manual, then pull the old relay straight out and press the new one firmly into the same socket until it seats. After installation, use a scan tool to clear any stored transmission or TCM fault codes before test-driving. No special torque or programming is required for a standard relay replacement on most Lexus Lx470 applications.

Frequently asked questions

How much does it cost to replace transmission control relays on a Lexus Lx470?
Parts start at $606.95 at AutoBuffy. A standalone relay is one of the least expensive electrical repairs on any vehicle. If you replace it yourself, total cost is the relay price plus minimal supplies. Shop labor, if needed, is usually under an hour since the relay is accessible in the fuse box.
Can a bad transmission control relay cause limp mode on a Lexus Lx470?
Yes. When the transmission control relay fails or supplies intermittent voltage, the TCM loses the stable power it needs to command shift solenoids. The transmission defaults to a fixed limp-mode gear as a protective measure. Replacing the relay and clearing stored fault codes typically restores normal shift behavior immediately.
How do I test the transmission control relay on my Lexus Lx470 before replacing it?
Remove the relay from the fuse box and use a multimeter to check coil resistance between the control terminals — an open or out-of-spec reading confirms failure. You can also apply 12 V directly to the coil and listen for an audible click while probing the switched terminals for continuity. A relay that passes bench testing but fails under heat should still be replaced.
Is the transmission control relay the same as the TCM fuse on a Lexus Lx470?
No. The fuse protects the circuit from overcurrent, while the relay is an electromechanical switch that applies or removes power to the TCM and transmission solenoids on command. Both should be inspected when diagnosing a TCM power-loss fault — a blown fuse often points to a shorted relay or wiring issue upstream.
How long does a transmission control relay last on a Lexus Lx470?
Relay service life varies widely. Most last the life of the vehicle under normal conditions, but heat soak near the engine bay, high electrical load cycles, and corrosion inside the fuse box can shorten lifespan considerably. Relays on vehicles used for frequent short trips cycle their contacts more often and tend to wear out sooner.
Will a bad transmission control relay throw a fault code on a Lexus Lx470?
Often yes. A failed relay typically sets TCM power-supply or transmission-range fault codes, and may also trigger a U-series network communication code if the TCM drops off the CAN bus. Scanning for codes before replacing parts helps confirm the relay is the root cause rather than the TCM or wiring harness.

Shop transmission control relays by year for the Lexus Lx470

200620052004200320022001200019991998

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