1993 Lexus SC 400FACTORY OEM SERVICE PROCEDURE

Transmitter Battery Test

NOTE: This test is performed when remote operation becomes difficult or impossible. This condition may be caused by a weak battery. This test is not only for purpose of checking battery capacity.
  1. Remove screw from ignition key. Remove cover, "O" ring and battery. Connect 2 new 1.5 volt dry-cell batteries in series. Connect positive battery lead to transmitter battery receptacle side terminal. Connect negative battery lead to transmitter bottom terminal.See Fig 1.
  2. Push transmitter remote button on ignition key to activate remote operation. If remote operation is possible, replace transmitter battery. If remote operation is not possible, replace transmitter and ROM, located inside remote door lock ECU. Destroy old transmitter and ROM to prevent reuse.
Fig 1: Testing Transmitter Battery
G93I84077Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

Shop Manual-Ready ToolsCompare Repair QuoteQuote Shield Pro

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.

Rather have a pro handle this?

A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.

Comes to youSame-day available12-month warranty
Get a Free Quote

No obligation. See pricing before you book.