ECD SYSTEM (w/o DPF), Diagnostic DTC:P00B3, P00B4

DTC Code DTC Name
P00B3 Radiator Coolant Temperature Sensor Circuit Low
P00B4 Radiator Coolant Temperature Sensor Circuit High

DESCRIPTION

A thermistor is built into the engine coolant temperature (radiator) sensor, of which the resistance value varies according to the radiator side engine coolant temperature.

The structure of the sensor and its connection to the ECM are the same as those of the Intake Air Temperature (IAT) sensor.

Tech Tips

When either DTC P00B3 or P00B4 is set, the ECM enters fail-safe mode. During fail-safe mode, the radiator side engine coolant temperature is estimated to be 80°C (176°F) by the ECM and the radiator fan motors are operated until the pass condition is detected. Fail-safe mode continues until a pass condition is detected.

P00B3
DTC Detection Drive Pattern DTC Detection Condition Trouble Area
Ignition switch ON for 3 seconds or more

Short in engine coolant temperature (radiator) sensor circuit for 3 seconds

(1 trip detection logic)

  • Short in engine coolant temperature (radiator) sensor circuit

  • Engine coolant temperature (radiator) sensor

  • ECM
P00B4
DTC Detection Drive Pattern DTC Detection Condition Trouble Area
Ignition switch ON for 3 seconds or more

Open in engine coolant temperature (radiator) sensor circuit for 3 seconds

(1 trip detection logic)

  • Open in engine coolant temperature (radiator) sensor circuit

  • Engine coolant temperature (radiator) sensor

  • ECM
Related Data List
DTC No. Data List
P00B3 Radiator Coolant Temp
P00B4

Tech Tips

When either of these DTCs are set, check the engine coolant temperature (radiator) by selecting the following menu items on the GTS: Powertrain / Engine and ECT / Data List / Radiator Coolant Temp.

Temperature Displayed Malfunctions
-40°C (-40°F) Open circuit
140°C (284°F) Short circuit

MONITOR DESCRIPTION

The engine coolant temperature (radiator) sensor is used to monitor the radiator side engine coolant temperature. The engine coolant temperature (radiator) sensor has a thermistor with a resistance that varies according to the temperature of the engine coolant. When the coolant temperature is low, the resistance in the thermistor increases. When the temperature is high, the resistance drops. These variations in resistance are reflected in the voltage output from the sensor. The ECM monitors the sensor voltage and uses this value to calculate the radiator side engine coolant temperature. When the sensor output voltage deviates from the normal operating range, the ECM interprets this as a fault in the engine coolant temperature (radiator) sensor and sets a DTC.

Example:

If the sensor voltage output is -40°C (-40°F) for 0.5 seconds or more, the ECM determines that there is an open in the engine coolant temperature (radiator) sensor circuit, and sets DTC P00B4. Conversely, if the voltage output is 140°C (284°F) for 0.5 seconds or more, the ECM determines that there is a short in the sensor circuit, and sets DTC P00B3.

If the malfunction is not repaired successfully, a DTC is set 0.5 seconds after the engine is next started.

WIRING DIAGRAM

A003I8HE15

INSPECTION PROCEDURE

Note

After replacing the ECM, the new ECM needs registration Click here and initialization Click here.

Tech Tips


  • 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 the GTS. Freeze frame data records 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, and other data from the time the malfunction occurred.

PROCEDURE


  1. READ VALUE USING GTS (RADIATOR COOLANT TEMPERATURE)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON and turn the GTS on.

    3. Enter the following menus: Powertrain / Engine and ECT / Data List / Radiator Coolant Temp.

    4. Read the value.

      Standard
      Between 80°C and 97°C (176°F and 207°F) with warm engine.
      Result
      Result Proceed to
      -40°C (-40°F) A
      140°C (284°F) B
      Between 80°C and 97°C (176°F and 207°F) C

      Tech Tips


      • If there is an open circuit, the GTS indicates -40°C (-40°F).

      • If there is a short circuit, the GTS indicates 140°C (284°F).


    B

    READ VALUE USING GTS (CHECK FOR SHORT IN HARNESS) Click here

    C

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

    A

  2. READ VALUE USING GTS (CHECK FOR OPEN HARNESS)


    1. Confirm good connection of the connector to the ECM.

    2. A003ETTE04
      Text in Illustration
      *1 Engine Coolant Temperature (Radiator) Sensor
      *2 ECM
      *a

      Front view of wire harness connector

      (to Engine Coolant Temperature [Radiator] Sensor)

      Disconnect the engine coolant temperature (radiator) sensor connector.

    3. Connect terminals 1 and 2 of the engine coolant temperature (radiator) sensor connector on the wire harness side.

    4. Connect the GTS to the DLC3.

    5. Turn the ignition switch to ON and turn the GTS on.

    6. Enter the following menus: Powertrain / Engine and ECT / Data List / Radiator Coolant Temp.

    7. Read the value.

      Standard
      140°C (284°F)

    8. Reconnect the engine coolant temperature (radiator) sensor connector.


    OK

    CONFIRM GOOD CONNECTION TO SENSOR. IF OK, REPLACE ENGINE COOLANT TEMPERATURE (RADIATOR) SENSOR. Click here

    NG

    READ VALUE USING GTS (CHECK FOR OPEN IN ECM) Click here

  3. READ VALUE USING GTS (CHECK FOR OPEN IN ECM)


    1. Disconnect the engine coolant temperature (radiator) sensor connector.

    2. Disconnect the ECM connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      B29-2 - B72-59 (RTHW) Always Below 1 Ω
      B29-1 -D98-74 (E2) Always Below 1 Ω

    4. Reconnect the engine coolant temperature (radiator) sensor connector.

    5. Reconnect the ECM connector.


    OK

    CONFIRM GOOD CONNECTION TO SENSOR. IF OK, REPLACE ECM. Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR Click here

  4. READ VALUE USING GTS (CHECK FOR SHORT IN HARNESS)


    1. A003GSZE14
      Text in Illustration
      *1 Engine Coolant Temperature (Radiator) Sensor
      *2 ECM

      Disconnect the engine coolant temperature (radiator) sensor connector.

    2. Connect the GTS to the DLC3.

    3. Turn the ignition switch to ON and turn the GTS on.

    4. Enter the following menus: Powertrain / Engine and ECT / Data List / Radiator Coolant Temp.

    5. Read the value.

      Standard
      -40°C (-40°F)

    6. Reconnect the engine coolant temperature (radiator) sensor connector.


    OK

    REPLACE ENGINE COOLANT TEMPERATURE (RADIATOR) SENSOR Click here

    NG

    CHECK HARNESS AND CONNECTOR (ENGINE COOLANT TEMPERATURE [RADIATOR] SENSOR - ECM) Click here

  5. CHECK HARNESS AND CONNECTOR (ENGINE COOLANT TEMPERATURE [RADIATOR] SENSOR - ECM)


    1. Disconnect the ECM connectors.

    2. Disconnect the engine coolant temperature (radiator) sensor connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      B72-59 (RTHW) or B29-2 - Body ground Always 10 kΩ or higher
      D98-74 (E2) or B29-1 - Body ground Always 10 kΩ or higher

    4. Reconnect the ECM connectors.

    5. Reconnect the engine coolant temperature (radiator) sensor connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR Click here

    OK

  6. REPLACE ECM


    1. Replace the ECM Click here.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  7. CONFIRM GOOD CONNECTION TO SENSOR. IF OK, REPLACE ENGINE COOLANT TEMPERATURE (RADIATOR) SENSOR.


    1. Replace the engine coolant temperature (radiator) sensor Click here.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  8. REPAIR OR REPLACE HARNESS OR CONNECTOR


    1. Repair or replace the harness or connector.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  9. CONFIRM GOOD CONNECTION TO SENSOR. IF OK, REPLACE ECM.


    1. Replace the ECM Click here.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  10. REPLACE ENGINE COOLANT TEMPERATURE (RADIATOR) SENSOR


    1. Replace the engine coolant temperature (radiator) sensor Click here.


    NEXT

  11. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Connect the GTS to the DLC3.

    2. Clear the DTCs Click here.

    3. Turn the ignition switch to ON for 1 second.

    4. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

    5. Confirm that the DTC is not output again.


    NEXT

    END