Inspection Procedure

HINT:

In case of using the hand-held tester, start the inspection step  1 and in case of not using the hand-held tester, start from step  2.

1. READ VALUE OF HAND-HELD TESTER 
   1. Connect the hand-held tester to the DLC3.
   2. Check the cooler (ambient temp. sensor) thermistor using DATA LIST.

   Result: 

   COOLER (AMBIENT TEMP. SENSOR) THERMISTOR
   
   

   A	NG
   B	OK (Checking from the PROBLEM SYMPTOMS TABLE )
   C	OK (Checking from the DTC)

   1. B: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN  PROBLEM SYMPTOMS TABLE  
   2. C: Go to step   5 
   3. A: GO TO NEXT STEP 
2. INSPECT ECM (TAM - E2) 
   1. Remove the ECM with connectors still connected.
   2. Turn the ignition switch to the "ON" position.
   3. Measure the voltage between terminal TAM and E2 of ECM connector at each temperature.
      Fig 1: Inspecting ECM (TAM - E2)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard: 

      • 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.

   Result: 

   TAM AND E2 OF ECM CONNECTOR
   
   

   A	NG
   B	OK (Checking from the PROBLEM SYMPTOMS TABLE )
   C	OK (Checking from the DTC)

   1. B: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN  PROBLEM SYMPTOMS TABLE  
   2. C: Go to step   5 
   3. A: GO TO NEXT STEP 
3. INSPECT COOLER (AMBIENT TEMP. SENSOR) THERMISTOR 
   1. Remove cooler (ambient temp. sensor) thermistor.
   2. Measure the resistance according to the value(s) in COOLER (AMBIENT TEMP. SENSOR) THERMISTOR  .

      Standard: 

      COOLER (AMBIENT TEMP. SENSOR) THERMISTOR
      
      

      Tester connection	Condition	Specified condition
      A1-1 - A1-2	10°C (50°F)	3.00 to 3.73 kΩ
      A1-1 - A1-2	15°C (59°F)	2.45 to 2.88 kΩ
      A1-1 - A1-2	20°F (68°F)	1.95 to 2.30 kΩ
      A1-1 - A1-2	25°C (77°F)	1.60 to 1.80 kΩ
      A1-1 - A1-2	30°C (86°F)	1.28 to 1.47 kΩ
      A1-1 - A1-2	35°C (95°F)	1.00 to 1.22 kΩ
      A1-1 - A1-2	40°C (104°F)	0.80 to 1.00 kΩ
      A1-1 - A1-2	45°C (113°F)	0.65 to 0.85 kΩ
      A1-1 - A1-2	50°C (122°F)	0.50 to 0.70 kΩ
      A1-1 - A1-2	55°C (131°F)	0.44 to 0.60 kΩ
      A1-1 - A1-2	60°C (140°F)	0.36 to 0.50 kΩ

   Fig 2: Inspecting Cooler (Ambient Temp. Sensor) Thermistor

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   NOTE:

   • Even slightly touching the sensor may change the resistance value. Be sure to hold the connector of the sensor.
   • When measuring the sensor temperature, it must be the same as the ambient temperature.

   HINT:

   As the temperature increases, the resistance decreases (see the graph on Fig 3).

   Fig 3: Temperature To Resistance Graph

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. NG: REPLACE COOLER (AMBIENT TEMP. SENSOR) THERMISTOR 
   2. OK: GO TO NEXT STEP 
4. CHECK HARNESS AND CONNECTOR (ECM - COOLER (AMBIENT TEMP. SENSOR) THERMISTOR) 
   1. Check for an open or short circuit in harness and connector between terminal TAM of ECM and cooler (ambient temp. sensor) thermistor (See ELECTRONIC CIRCUIT INSPECTION PROCEDURE ).
   1. NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 
   2. OK: GO TO NEXT STEP 
5. CHECK HARNESS AND CONNECTOR (COOLER (AMBIENT TEMP. SENSOR) THERMISTOR - ECM) 
   1. Check for an open or short circuit in harness and connector between cooler (ambient temp. sensor) thermistor and terminal E2 of ECM (See ELECTRONIC CIRCUIT INSPECTION PROCEDURE ).
   1. NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 
   2. OK: GO TO NEXT STEP 
6. CHECK READ OUTPUT DTC 
   1. Clear the DTCs.
   2. Read the DTC at least 8.5 minutes after turning the ignition switch to the "ON" position.

      Standard: Normal codes are output. 

   1. NG: REPLACE ECM 
   2. OK: USE SIMULATION METHOD TO CHECK