Drivers Door ECU/Master Switch Improvement
ELECTRICALEL004-00
April 28, 2000
Title:
DRIVER'S DOOR ECU/MASTER
SWITCH IMPROVEMENT
Models:
'99 RX 300
Introduction
The driver's door ECU/Master Switch has been improved with new software. When the ECU program becomes temporarily disabled, one or more of the following concerns may occur.
1. The driver's side door lock won't lock/unlock electrically when operating from the master switch or wireless key, but will operate with the manual control.
2. The multiplex communication continues transmitting data after the ignition is turned off and all doors are closed. (Battery drain stays at 1.4 - 1.6 amps.)
3. The door ajar light remains illuminated with the doors closed.
4. The power windows may not operate properly from the master switch.
5. The room lamp does not turn on while the door is open, the room lamp switch is in the door position and the courtesy lamp in the door is ON.
DIAGNOSIS:
1. There are no other multiplex concerns that are related to the master switch aside from the 5 possible concerns listed above.
2. Before replacing any components, disconnect and reconnect the battery and then reconfirm the customer's complaint. If the customer's complaint has not been corrected, the master switch is not at fault and the source of the complaint lies elsewhere.
Applicable Vehicles
^ 1999 model year RX 300
Warranty Information
Applicable Warranty *:
This repair is covered under the LEXUS Basic Warranty. This warranty is in effect for 48 months or 50,000 miles, whichever occurs first, from the vehicle's in-service date.
* Warranty application is limited to correction of a problem based upon a customer's specific complaint.
Production Change Information
Parts Information
Repair Procedure
^ Confirm the complaint matches one or more of the items 1-5.
^ Disconnect the battery or reconnect after 1 minute. If, and only if, the complaint item(s) are now corrected, replace the master switch. If the complaint item(s) remain, the problem is not related to the ECU logic and will not be corrected by replacing the master switch.
^ Countermeasure parts can be identified by a part package label date code of 9108 or higher. Date is coded where; "9" = 1999, the letter "I" = the 9th month, and "08" = the date.