Inspection Procedure

WARNING: This page is about a different car, the 2007 Toyota Land Cruiser. However, it is still accessible from the selected car via links, so may be relevant.

CHECK REAR AIR CONDITIONING AMPLIFIER
1. Remove the rear A/C amplifier with the connectors still connected.
2. Turn ignition switch to ON.
3. Measure voltage between terminals TINR (A32-8) and SG1 (A32-9) 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 26 is display, check and replace the rear A/C amplifier.
OK: REPLACE REAR AIR CONDITIONING AMPLIFIER

Fig 1: Checking Rear Air Conditioning Amplifier
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: GO TO NEXT STEP
CHECK REAR INLET AIR TEMPERATURE SENSOR
1. Disconnect the R26 rear inlet air temperature sensor connector.
2. Measure resistance between terminals 1 and 2 of the rear inlet air 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 resistance decreases.
NG: REPLACE REAR INLET AIR TEMPERATURE SENSOR

Fig 2: Identifying R26 Rear Inlet Air Temperature Sensor Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

OK: REPLACE REAR AIR CONDITIONING AMPLIFIER