SFI SYSTEM (w/o EGR System), Diagnostic DTC:P261B, P261C, P261D

DTC Code DTC Name
P261B Engine Coolant Pump "B" Control Malfunction
P261C Engine Coolant Pump "B" Control Circuit Low
P261D Engine Coolant Pump "B" Control Circuit High

DESCRIPTION

The ECM controls the engine water pump assembly by calculating the necessary amount of coolant flow based on engine coolant temperature, engine speed and vehicle speed information. The speed of the engine water pump assembly is controlled steplessly using a duty cycle signal sent from the ECM. This optimal control enhances warm-up performance and reduces cooling losses, thus reducing the specific fuel consumption of the engine.

DTC No. DTC Detection Condition Trouble Area
P261B Engine water pump assembly speed is less than 900 rpm while the engine water pump assembly is operating (1 trip detection logic).
  • Open or short in engine water pump assembly circuit

  • Engine water pump assembly

  • ECM

P261C Engine water pump assembly output voltage is less than specified value while the engine water pump assembly is operating (1 trip detection logic).
  • Short in engine water pump assembly circuit

  • Engine water pump assembly

  • ECM

P261D Engine water pump assembly output voltage is higher than specified value while the engine water pump assembly is operating (1 trip detection logic).
  • Open in engine water pump assembly circuit

  • Engine water pump assembly

  • ECM

MONITOR DESCRIPTION

The ECM calculates the speed of the engine water pump assembly using a duty cycle signal sent from the engine water pump assembly. When the speed of the engine water pump assembly becomes less than 900 rpm while it is operating, the ECM detects the malfunction and stores DTC P261B.

The engine water pump assembly operates steplessly based on a duty cycle signal sent from the ECM. If actual drive duty cycle ratio does not correspond to the target drive duty cycle of the engine water pump assembly, the ECM detects the malfunction and stores DTC P261C or P261D.

MONITOR STRATEGY

Required Sensors/Components (Main) Engine water pump assembly
Frequency of Operation Continuous

CONFIRMATION DRIVING PATTERN


  1. Connect the intelligent tester to the DLC3.

  2. Turn the power switch on (IG) and turn the tester on.

  3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC operation).

  4. Turn the power switch off and wait for at least 30 seconds.

  5. Turn the power switch on (IG) and turn the tester on.

  6. Put the engine in inspection mode (maintenance mode) Click here.

  7. Start the engine and warm it up (until the engine coolant temperature is 75°C (167°F) or higher) [B].

  8. Idle the engine for 20 seconds or more [A].

  9. Enter the following menus: Powertrain / Engine and ECT / DTC [B].

  10. Read the pending DTCs.

    Tech Tips


    • If a pending DTC is output, the system is malfunctioning.

    • If a pending DTC is not output, perform the following procedure.

  11. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

  12. Input the DTC: P261B, P261C or P261D.

  13. Check the DTC judgment result.

    Tester Display Description
    NORMAL
    • DTC judgment completed

    • System normal

    ABNORMAL
    • DTC judgment completed

    • System abnormal

    INCOMPLETE
    • DTC judgment not completed

    • Perform driving pattern after confirming DTC enabling conditions

    N/A
    • Unable to perform DTC judgment

    • Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    Tech Tips


    • If the judgment result shows NORMAL, the system is normal.

    • If the judgment result shows ABNORMAL, the system has a malfunction.

    • If the judgment result shows INCOMPLETE or N/A, perform steps [A] and [B] again.

WIRING DIAGRAM

A003W53E05

INSPECTION PROCEDURE

Note

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

Tech Tips

Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. 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.

PROCEDURE


  1. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (ACTIVATE THE ELECTRIC WATER PUMP)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the tester on.

    4. Enter the following menus: Powertrain / Engine and ECT / Active Test / Activate the Electric Water Pump.

    5. Touch the engine water pump assembly and check that the pump is operating (vibrating).

      OK
      The engine water pump assembly is operating (vibrating).

    NG
    OK
  2. CHECK HARNESS AND CONNECTOR (ENGINE WATER PUMP ASSEMBLY - ECM)

    Tech Tips

    Confirm a good connection at the engine water pump assembly and ECM connectors.


    1. Disconnect the engine water pump assembly 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
      D13-2 (NWP) - A60-11 (WPI) Always Below 1 Ω
      D13-4 (SWP) - A60-10 (WPO) Always Below 1 Ω
      D13-2 (NWP) or A60-11 (WPI) - Body ground Always 10 kΩ or higher
      D13-4 (SWP) or A60-10 (WPO) - Body ground Always 10 kΩ or higher

    NG
    OK
  3. CHECK TERMINAL VOLTAGE (WPI VOLTAGE)


    1. A003XZWE12
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Engine Water Pump Assembly)

      Disconnect the engine water pump assembly connector.

    2. Turn the power switch on (IG).

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      D13-2 (NWP) - Body ground Power switch on (IG) 11 to 14 V

    NG
    OK
  4. CHECK TERMINAL VOLTAGE (POWER SOURCE OF ENGINE WATER PUMP ASSEMBLY)

    Tech Tips

    Confirm a good connection at the engine water pump assembly and ECM connectors.


    1. A003XZWE13
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Engine Water Pump Assembly)

      Disconnect the engine water pump assembly connector.

    2. Turn the power switch on (IG).

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      D13-1 (+B) - Body ground Power switch on (IG) 11 to 14 V

    NG
    OK
  5. CHECK HARNESS AND CONNECTOR (ENGINE WATER PUMP ASSEMBLY - BODY GROUND)


    1. Disconnect the engine water pump assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D13-5 (PGND) - Body ground Always Below 1 Ω

    NG
    OK
  6. CHECK HARNESS AND CONNECTOR (ENGINE WATER PUMP ASSEMBLY - ECM)


    1. Disconnect the engine water pump assembly 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
      D13-2 (NWP) - A60-11 (WPI) Always Below 1 Ω
      D13-4 (SWP) - A60-10 (WPO) Always Below 1 Ω
      D13-2 (NWP) or A60-11 (WPI) - Body ground Always 10 kΩ or higher
      D13-4 (SWP) or A60-10 (WPO) - Body ground Always 10 kΩ or higher

    NG
    OK
  7. REPLACE ENGINE WATER PUMP ASSEMBLY


    1. Replace the engine water pump assembly Click here.


    NEXT
  8. CHECK WHETHER DTC OUTPUT RECURS (DTC P261B, P261C OR P261D)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the tester on.

    4. Clear the DTCs Click here.

    5. Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.

    6. Enter the following menus: Powertrain / Engine and ECT / DTC.

    7. Read the DTCs.

      Result
      Result Proceed to
      DTC P261B, P261C or P261D is output A
      DTC is not output B

    B
    A
  9. INSPECT RELAY (ENG W/P RELAY)


    1. A003X7UE01

      Remove the ENG W/P relay from the engine room relay block and junction block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3 - 5 No auxiliary battery voltage applied between terminals 1 and 2 10 kΩ or higher
      3 - 5 Auxiliary battery voltage applied between terminals 1 and 2 Below 1 Ω

    NG
    OK
  10. CHECK HARNESS AND CONNECTOR (ENG W/P RELAY - ENGINE WATER PUMP ASSEMBLY)


    1. Remove the ENG W/P relay from the engine room relay block and junction block assembly.

    2. Disconnect the engine water pump assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      ENG W/P relay terminal 5 - D13-1 (+B) Always Below 1 Ω
      ENG W/P relay terminal 5 or D13-1 (+B) - Body ground Always 10 kΩ or higher

    NG
    OK
  11. CHECK TERMINAL VOLTAGE (POWER SOURCE OF ENG W/P RELAY)


    1. A003ZCOE01
      Text in Illustration
      *1 Engine Room Relay Block and Junction Block Assembly

      Remove the ENG W/P relay from the engine room relay block and junction block assembly.

    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      ENG W/P relay terminal 3 - Body ground Always 11 to 14 V

    NG
    OK
  12. CHECK HARNESS AND CONNECTOR (ENG W/P RELAY - BODY GROUND)


    1. Remove the ENG W/P relay from the engine room relay block and junction block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      ENG W/P relay terminal 1 - Body ground Always Below 1 Ω

    NG
    OK