1998 Lexus GS 400 air conditijoner

Hi barrymarkowitz,

Thank you for the donation.

Seems the air mix doors are not functioning correctly. Perform trouble codes retrieval to see if any are present.

RETRIEVING CODES
1. While pressing and holding AUTO button and recirculated/fresh air button, turn ignition on. Indicators will flash on and off at one-second intervals, 4 times in succession, and a tone will sound as an indicator check. Press OFF button to cancel indicator check.

2. After indicator check is complete, system will enter self-diagnostic mode. Stored trouble codes will appear in sequence on driver's side temperature display.

3. Press driver's side temperature switch to display codes one at a time. If tone sounds when code is displayed, problem causing code currently exists. If tone does not sound when code is displayed, associated problem is past history, and does not currently exist. Press OFF button to exit self-diagnostics.

© 2008 Mitchell Repair Information Co., LLC.

Attempt to retrieve codes did not work. Indicators did flash four times, but no tone sounded.
Then display flashed 00 where driver's temperature is displayed and seat belted figure also flashed. This went on indefinitely. What now?

As no codes are detected, the next thing you need to do is to check the air mix servomotor functions.

Removing the air mix servomotor is not going to b easy as it involves removing the heater unit.