2000 Lexus ES 300 remote key use

WSBALLINGER

MEMBER
2000 LEXUS ES 300
6 CYL
FWD
AUTOMATIC
99,000 MILES

My key will unlock my doors but the botton which locks my doors and turns off the headlights will not work. I have replaced the battery in the key. Also the same effect occurs if I use the spare key so I know it is not the key. The "panic" function which is part of the function of the same button on the key will also not work. A call to the dealer and they told me i'd need to pay for diagnostics first which would cost 120.00 to start with. Any thoughts?

1 Reply

DAVE H

MECHANIC
13,383 POSTS

SYSTEM OPERATION CHECK
NOTE:This check verifies that door lock ECU receives and recognizes signals from remote transmitter. Perform this check when remote transmitter does not operate properly. If remote transmitter operates properly and problems still exist, diagnose by symptom. See SYMPTOM DIAGNOSIS.

Remove key from ignition switch. Close and lock all doors. Ensure buzzer volume is set to maximum. Go to next step.
While standing outside vehicle near driver's door, point transmitter toward vehicle. Press door LOCK, and then UNLOCK button on transmitter for about one second. If doors do not lock and unlock properly, go to next step. If doors lock and unlock properly, system is okay at this time.
Check transmitter battery voltage (6 volts) or replace battery and recheck door lock operation using transmitter. If door locks still do not operate, go to next step.
NOTE:Remove key from ignition switch. Close and lock all doors. Ensure buzzer volume is set to maximum.

Perform the following within 35 seconds: insert key into ignition switch, and then remove it. Insert key once more. Turn ignition on, and then off one time within 5 seconds. Within 30 seconds, turn ignition on and off 9 additional times. Buzzer should sound a short tone followed by a longer tone, indicating successful entry to diagnostic mode. If buzzer sounds as specified, go to next step. If buzzer does not sound, go to step 8.
Press LOCK button on transmitter. Buzzer should produce a short tone about every.5 second. Press UNLOCK button on transmitter. Buzzer should alternate a short tone about every.5 second, then.25 second. Press luggage compartment button. Buzzer should produce a long tone about every.5 second. If buzzer operates as specified, go to next step. If buzzer does not operate for each button pressed, go to step 9. If buzzer sounds a long continuous tone, go to step 10.
Standing at least 3 feet from vehicle, press and hold any transmitter button. After holding button for 20 seconds, buzzer should stop. If operation is not as specified, go to next step. If operation is as specified, go to step 11.
Repeat procedure in step 6 using a known-good transmitter and check effective range. If buzzer operates as specified, replace original transmitter. If buzzer does not operate properly using either transmitter, wireless door lock ECU is faulty.
Ensure step 4 was performed correctly. Repeat if necessary, and then go to step 5. If step 4 was performed correctly, but buzzer does not sound, replace wireless door lock buzzer. If buzzer sounds, but diagnostic mode cannot be entered, go to step 12.
Transmitter or wireless door lock ECU is faulty. Use a known-good transmitter to re-enter diagnostic mode. If operation is okay, replace original transmitter. If operation is not okay, wireless door lock ECU is faulty.
A long continuous tone indicates transmitter is operating, but transmitter code is not recognized by ECU. Program transmitter. See PROGRAMMING. Recheck remote door lock operation. If transmitter cannot be programed, go to next step.
Check wireless door lock ECU circuit. See WIRELESS DOOR LOCK ECU CIRCUIT under CIRCUIT TESTS. Replace ECU if necessary. If ECU is okay, check and repair system wire harness. See WIRING DIAGRAMS.
With wireless door lock ECU connected, measure voltage (backprobe) between ground and terminal No. 10 (Blue/Black wire) at wireless door lock ECU harness connector. Voltage should be zero volts with key inserted into ignition key cylinder, and battery voltage with key removed. Measure voltage (backprobe) between ground and terminal No. 13 (Black/Red wire) at wireless door lock ECU harness connector. Voltage should be zero volts with ignition off, and battery voltage with ignition on. Repair circuits as necessary. If circuits are okay, wireless door lock ECU is faulty.