Inspection Procedure

WARNING: This page is about a different car, the 2006 Toyota Land Cruiser. However, it is still accessible from the selected car via links, so may be relevant.

CHECK AIR CONDITIONING AMPLIFIER
1. Remove the rear A/C amplifier with the connectors still connected.
2. Turn the ignition switch ON.
3. Measure the voltage between terminals TRR (A33-7) and SG2 (A33-2) of the rear A/C amplifier connector at each temperature.
  Standard voltage: 1.8 to 2.2 V at 25°C (77°F)
  
  1.2 to 1.6 V at 40°C (104°F)
  
  HINT:
  - As the temperature increases, the voltage decreases.
  - However, if DTC 19 is displayed, check and replace the A/C amplifier.
OK: REPLACE REAR AIR CONDITIONING AMPLIFIER

Fig 1: Measuring Voltage Between Terminals TRR (A33-7) & SG2 (A33-2) Of Rear A/C Amplifier Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: GO TO NEXT STEP
INSPECT REAR ROOM TEMPERATURE SENSOR
1. Disconnect the R34 rear room temperature sensor connector.
2. Measure the resistance between terminals 1 and 2 of the room temperature sensor connector at each temperature.
  Standard resistance: 1.65 to 1.75 kΩ at 25°C (77°F)
  
  0.55 to 0.65 kΩ at 50°C (122°F)
  
  HINT:
  - As the temperature increases, the voltage decreases.
  - However, if DTC 19 is displayed, check and replace the A/C amplifier.
NG: REPLACE REAR ROOM TEMPERATURE SENSOR

Fig 2: Inspecting Rear Room Temperature Sensor
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: GO TO NEXT STEP
CHECK WIRE HARNESS (REAR AIR CONDITIONING AMPLIFIER - REAR ROOM TEMPERATURE SENSOR)
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR

OK: REPLACE REAR AIR CONDITIONING AMPLIFIER