Inspection Procedure

HINT:

If other DTCs relating to different systems that have terminal E2 as the ground terminal are output simultaneously, terminal E2 may have an open circuit.
Read freeze frame data using an intelligent tester. Freeze frame data record the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data, from the time the malfunction occurred.

READ VALUE USING INTELLIGENT TESTER (ENGINE COOLANT TEMPERATURE)

Connect an intelligent tester to the DLC3.
Turn the ignition switch ON.
Turn the tester ON.
Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / COOLANT TEMP.

Read the value displayed on the tester.

Standard:

80°C to 97°C (176°F to 207°F) with warm engine.

Result

DTC RESULT DESCRIPTION

Temperature Displayed	Proceed To
-40°C (-40°F)	A
140°C (284°F) or higher	B
80°C to 97°C (176°F to 207°F)	C

HINT:

If there is an open circuit, the intelligent tester indicates -40°C (-40°F).
If there is a short circuit, the intelligent tester indicates 140°C (284°F) or higher.

B: Go to step 4

C: CHECK FOR INTERMITTENT PROBLEMS

A: Go TO NEXT STEP

READ VALUE USING INTELLIGENT TESTER (CHECK FOR OPEN IN WIRE HARNESS)
1. Disconnect the B19 Engine Coolant Temperature (ECT) sensor connector.
  
  Fig 1: Identifying B19 Engine Coolant Temperature (ECT) Sensor Connector
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Connect terminals 1 and 2 of the ECT sensor connector on the wire harness side.
3. Connect an intelligent tester to the DLC3.
4. Turn the ignition switch ON.
5. Turn the tester ON.
6. Select the following menu items: DIAGNOSIS/ ENHANCED OBD 11 / DATA LIST / PRIMARY / COOLANT TEMP.
7. Read the value displayed on the tester.
  Standard:
  
  140°C (284°F) or higher
8. Reconnect the ECT sensor connector.
OK: CONFIRM GOOD CONNECTION TO SENSOR. IF OK, REPLACE ENGINE COOLANT TEMPERATURE SENSOR (See REMOVAL )

NG: Go TO NEXT STEP
READ VALUE USING INTELLIGENT TESTER (CHECK FOR OPEN IN ECM)
1. Disconnect the B19 ECT sensor connector.
  
  Fig 2: Identifying B19 ECT Sensor Connector
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Connect terminals THW and E2 of the B1 ECM connector.
  HINT:
  
  Before checking, do visual and contact pressure checks on the ECM connector.
3. Connect an intelligent tester to the DLC3.
4. Turn the ignition switch ON.
5. Turn the tester ON.
6. Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / COOLANT TEMP.
7. Read the value displayed on the tester.
  Standard:
  
  140°C (284°F) or higher
8. Reconnect the ECT sensor connector.
OK: REPAIR OR REPLACE HARNESS OR CONNECTOR

NG: CONFIRM GOOD CONNECTION TO ECM. IF OK, REPLACE ECM (See REMOVAL )
READ VALUE USING INTELLIGENT TESTER (CHECK FOR SHORT IN WIRE HARNESS)
1. Disconnect the B19 ECT sensor connector.
  
  Fig 3: Identifying B19 ECT Sensor Connector
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Connect an intelligent tester to the DLC3.
3. Turn the ignition switch ON.
4. Turn the tester ON.
5. Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / COOLANT TEMP.
6. Read the value displayed on the tester.
  Standard:
  
  -40°C (-40°F)
7. Reconnect the ECT sensor connector.
OK: REPLACE ENGINE COOLANT TEMPERATURE SENSOR (See REMOVAL )

NG: Go TO NEXT STEP
READ VALUE USING INTELLIGENT TESTER (CHECK FOR SHORT IN ECM)
1. Disconnect the B1 ECM connector.
  
  Fig 4: Identifying B1 ECM Connector
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Connect an intelligent tester to the DLC3.
3. Turn the ignition switch ON.
4. Turn the tester ON.
5. Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / COOLANT TEMP.
6. Read the value displayed on the tester.
  Standard:
  
  -40°C (-40°F)
7. Reconnect the ECM connector.
OK: REPAIR OR REPLACE HARNESS OR CONNECTOR

NG: REPLACE ECM (See REMOVAL )