Inspection Procedure

WARNING: This page is about a different car, the 2004 Lexus ES 330. However, it is still accessible from the selected car via links, so may be relevant.

CHECK HARNESS AND CONNECTOR(BETWEEN A/C AMPLIFIER AND SEAT HEATER)
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step.
INSPECT HEATER CONTROL HOUSING SUB-ASSY (SHPT, SHPE)
1. Remove A/C amplifier with connector.
2. Turn the ignition switch ON.
3. Measure voltage between terminals SHPT, SHPE and SHPE of A/C amplifier and body ground.
  
  Fig 1: Measuring Voltage Between Terminals SHPT, SHPE And SHPE Of A/C Amplifier And Body Ground
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Standard
  
  Fig 2: Voltage Results Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
HINT: The temperature in this case means the value that the seat heater sensor senses, not that the seat surface.

NG: REPLACE A/C AMPLIFIER

OK: GO TO SEAT HEATER CIRCUIT