ECD SYSTEM, Diagnostic DTC:P1021

DTC Code DTC Name
P1021 Charged Air Cooler Downstream Temperature Sensor

DESCRIPTION

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

P1021

Charged Air Cooler Downstream Temperature Sensor

After 1 or more hours elapse with ignition switch off, the difference between EGR the temperature and intake air temperature is equal to or higher than the threshold.

(3 trip detection logic)

  • Open or short in intake air temperature sensor circuit

  • Intake air temperature sensor

  • Open or short in EGR gas temperature sensor circuit

  • EGR gas temperature sensor

  • ECM

Does not come on

DTC stored
Tip:

The threshold used for DTC detection is calculated based on the engine stop time.

Table 1. Related Data List

DTC No.

Data List

P1021

  • Temperature Down Stream of EGR Cooler

  • Intake air temp (Turbo)

WIRING DIAGRAM

Refer to DTC P007C.

Click here

Refer to DTC P040C.

Click here

CAUTION / NOTICE / HINT

Note:

When replacing the ECM, the ECM needs registration and initialization.

Click here

Tip:

  • When the ECM must be replaced, before replacing the ECM, perform the "Learning Values Save" function using the GTS. Then after installing the new ECM, perform all of the initialization/registrations for the "Learning Values Write" function by following the instructions shown on the GTS display.

  • 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. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO P1021)

    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 / Trouble Codes.

      Powertrain > Engine and ECT > Trouble Codes

    4. Read the DTCs.

      Result

      Result

      Proceed to

      DTC P1021

      A

      DTC P1021 and other DTCs

      B
      Tip:

      If any DTCs other than P1021 are output, troubleshoot those DTCs first.

    B

    GO TO DTC CHART

    Click here

    A

  2. READ VALUE USING GTS

    1. Stop the engine when the coolant temperature is more than 78°C (173°F).

    2. Leave the vehicle.

      Tip:

      To meet the DTC detection conditions, the engine coolant temperature must drop to below 32°C (89°F).

    3. Connect the GTS to the DLC3.

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

    5. Start the engine when the engine coolant temperature is less than 32°C (89°F).

    6. Idle the engine for 1 minute or more.

    7. Enter the following menus: Powertrain / Engine and ECT / Data List / Temperature Down Stream of EGR Cooler and Intake Air Temp (Turbo).

      Powertrain > Engine and ECT > Data List

      Tester Display

      Intake Air Temp (Turbo)

      Temperature Down Stream of EGR Cooler

    8. Read the value of Temperature Down Stream of EGR Cooler on the GTS.

      Standard

      Difference between the Temperature Down Stream of EGR Cooler and actual outside air temperature is within 10°C (18°F) or less.

      Tip:

      Temperature readings on the vehicle outside temperature gauge (if equipped) are not suitable for comparing to the intake air temperature reading. The outside temperature gauge has a significant delay built in to prevent swings in the temperature display. Use an accurate thermometer to determine the outside air temperature.

    9. Read the value of Temperature Down Stream of EGR Cooler on the GTS.

      Standard

      Difference between the Temperature Down Stream of EGR Cooler and actual outside air temperature is within 10°C (18°F) or less.

      Tip:

      Temperature readings on the vehicle outside temperature gauge (if equipped) are not suitable for comparing to the intake air temperature reading. The outside temperature gauge has a significant delay built in to prevent swings in the temperature display. Use an accurate thermometer to determine the outside air temperature.

      Result

      Result

      Proceed to

      OK

      A

      NG (Temperature Down Stream of EGR Cooler value deviated)

      B

      NG (Intake Air Temp (Turbo) value deviated)

      C
    A

    REPLACE ECMClick here

    C

    INSPECT INTAKE AIR TEMPERATURE SENSORClick here

    B

  3. INSPECT EGR GAS TEMPERATURE SENSOR

    1. Inspect the EGR gas temperature sensor.

      Click here

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE EGR GAS TEMPERATURE SENSORClick here

    OK

  4. CHECK HARNESS AND CONNECTOR (EGR GAS TEMPERATURE SENSOR - ECM)

    1. Disconnect the EGR gas temperature 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

      B132-1 (THEC) - B112-118 (THEC)

      Always

      Below 1 Ω

      B132-2 (E2) - B112-86 (ETEC)

      Always

      Below 1 Ω

      B132-1 (THEC) or B112-118 (THEC) - Body ground

      Always

      10 kΩ or higher

      B132-2 (E2) or B112-86 (ETEC) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE ECMClick here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTORClick here

  5. REPLACE EGR GAS TEMPERATURE SENSOR

    1. Replace the EGR gas temperature sensor.

      Click here

    Result

    Proceed to

    NEXT
    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIREDClick here

  6. INSPECT INTAKE AIR TEMPERATURE SENSOR

    1. Inspect the intake air temperature sensor.

      Click here

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE INTAKE AIR TEMPERATURE SENSORClick here

    OK

  7. CHECK HARNESS AND CONNECTOR (INTAKE AIR TEMPERATURE SENSOR - ECM)

    1. Disconnect the intake air temperature 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

      B115-1 (THA) - B112-79 (THIA)

      Always

      Below 1 Ω

      B115-2 (E2) - B112-89 (ETHI)

      Always

      Below 1 Ω

      B115-1 (THA) or B112-79 (THIA) - Body ground

      Always

      10 kΩ or higher

      B115-2 (E2) or B112-89 (ETHI) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTORClick here

    OK

  8. REPLACE ECM

    1. Replace the ECM.

      Click here

    Result

    Proceed to

    NEXT
    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIREDClick here

  9. REPAIR OR REPLACE HARNESS OR CONNECTOR

    1. Repair or replace the harness or connector.

    Result

    Proceed to

    NEXT
    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIREDClick here

  10. REPLACE INTAKE AIR TEMPERATURE SENSOR

    1. Replace the intake air temperature sensor.

      Click here

    Result

    Proceed to

    NEXT
    NEXT

  11. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

    1. Connect the GTS to the DLC3.

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

    3. Clear the DTCs.

      Powertrain > Engine and ECT > Clear DTCs

    4. Turn the ignition switch off and wait for 60 seconds or more [A].

    5. Perform road test [B].

    6. Repeat [A] and [B] for the number of trips detected.

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

      Powertrain > Engine and ECT > Trouble Codes

    8. Confirm that the DTC is not output again.

    Result

    Proceed to

    NEXT
    NEXT

    END