1998 ES300 Found hidden diagnostic menu
 

So i have a 1998 Lexus ES300, and i was playing around with the cluster when i discovered that you can access a diagnostic mode by, turning the key to "ACC", then push & hold the Trip/Reset button for about five seconds, then while still holding the button, turn the key to "ON" and hold for a few more seconds, then release the Trip/Reset button. After you release the button press the Trip/Reset button once and the odometer will switch from your current mileage and display a "6" (or at least mine does) from here you can continue to push the button and scroll "1"-"20" (I imagine these are sub menus, or vehicle presets) To Select/Confirm an option hold the Trip/Reset button for about five seconds, then press the Trip/Reset button once again to resume normal operation.

What i wanted to know is what the number codes mean/do once you select them, i haven't swapped any settings in fear of activating the self-destruct mode, but i was wondering if anyone knows about this or, if i'm the first person to find this, hopefully someone will dig into this and we'll all learn something new!

I only ask that if you find/know anything to post it here, it'd be really cool if it has a diagnostic mode like Chrysler and Ford have!

The only other thing i've found out so far is that when the number "1" is on the display but not Confirmed/Selected, i can hear a relay click somewhere. But like i said i haven't changed any of the settings, in case it changes the ECM or i activate a hidden "Test Airbag" function and accidentally kill myself.

Happy Hunting!!!

I have no idea what you discovered!

I'm curious however, how you managed to discover the sequence that you used?

What were you trying to do?

Well before the Lexus I owned a 2000 Dodge Ram 3500 Cummins, and all Chrysler (Chrysler, Jeep, Dodge, Plymouth) and Ford (Ford, Mercury) products have a built in diagnostic mode. if you have a digital odometer just hold the Trip/Reset button, while the ignition is off, for five seconds. Then while still holding it, turn the key to "ON" and all your Gauges, LEDs, and digital displays will test, no menus or anything like that, it just starts testing. This is useful because you can check your bulbs, and if your check engine light is on, this test will also display all error codes in full on your odometer.

Knowing this, my Lexus will sometimes show the check engine light if you do a self test. Yes, the Lexus ES300 at least, does have a BASIC self test mode. just turn the key between ACC and ON, (your instrument cluster should be lit) ABS, Check engine, Battery, Oil pressure, TCS, and Airbag light should come on for a few seconds, then all should pop off, except for your oil light. any light that stays on after that, means that the ECM has detected a problem with that function, but hasn't yet, or cant store a code for it.

But anyways I was curious if my Lexus had a diagnostic mode similar to my dodge, and well I found, something...

Anyone else test this? With a different year model?

With all due respect to the OP, I may be wrong, but something doesn't smell right about his post.

going to check this on my 95 Ls400 right now..

Waddaya mean?

My 99 has the same setting. 6 appears to be the default setting, whatever it is. I haven't started my car with any other setting. I've tired a few and none appear to do anything. But I wouldn't mess with this. I might call Lexus later and see if they will shed some light on it.

Thanks, let us know if you find anything

I tried this on my 2002 ES300, all it did was reset my trip meter to zero :)