SFI 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.

MONITOR STRATEGY

Related DTCs

P261B: Engine water pump circuit performance

P261C: Engine water pump circuit range check (low voltage)

P261D: Engine water pump circuit range check (high voltage)
Required Sensors/Components (Main) Engine water pump assembly
Required Sensors/Components (Related) -
Frequency of Operation Continuous
Duration

15 seconds: Engine water pump circuit performance

3 seconds: Engine water pump circuit range check (low voltage, high voltage)
MIL Operation Immediate
Sequence of Operation None

TYPICAL ENABLING CONDITIONS

All
Monitor runs whenever the following DTCs are not stored None
All of the following conditions are met -
Auxiliary battery voltage 8 V or higher
Power switch On (IG)
Time after power switch off to on (IG) 0.5 seconds or more
P261B
All of the following conditions are met -
Output duty cycle 30% or more
Monitor synchronism monitor status Enable
Engine coolant temperature -10°C (14 °F) or higher
Engine coolant temperature sensor circuit fail (P0115, P0117, P0118) Not detected
Engine water pump circuit low voltage fail (P261C) Not detected
Engine water pump circuit high voltage fail (P261D) Not detected
P261C and P261D
Both of the following conditions are met -
Output duty cycle 30 to 85%
Engine water pump circuit performance fail (P261B) Not detected

TYPICAL MALFUNCTION THRESHOLDS

P261B
Engine water pump speed Less than 900 rpm
P261C
Both of the following conditions are met -
Engine water pump output terminal voltage level Low
Engine water pump output signal No signal
P261D
Both of the following conditions are met -
Engine water pump output terminal voltage level High
Engine water pump output signal No signal

COMPONENT OPERATING RANGE

P261B
Engine water pump speed 900 rpm or more
P261C and P261D
Engine water pump output signal Signal input

CONFIRMATION DRIVING PATTERN


  1. Connect the Techstream to the DLC3.

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

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

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

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

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

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

    Techstream 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.

  14. If no pending DTC is output, perform a universal trip and check for permanent DTCs Click here.

    Tech Tips


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

    • If no permanent DTC is output, the system is normal.

WIRING DIAGRAM

A01HTSCE02

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 Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.

PROCEDURE


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


    1. Connect the Techstream to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the Techstream on.

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

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

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

    NG

    CHECK TERMINAL VOLTAGE (POWER SOURCE OF ENGINE WATER PUMP ASSEMBLY) Click here

    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
      E66-2 (NWP) - A25-28 (WPI) Always Below 1 Ω
      E66-1 (SWP) - A25-29 (WPO) Always Below 1 Ω
      E66-2 (NWP) or A25-28 (WPI) - Body ground Always 10 kΩ or higher
      E66-1 (SWP) or A25-29 (WPO) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK TERMINAL VOLTAGE (WPI VOLTAGE)


    1. A01HTH4E03
      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
      E66-2 (NWP) - Body ground Power switch on (IG) 11 to 14 V

    NG

    REPLACE ECM Click here

    OK

    REPLACE ENGINE WATER PUMP ASSEMBLY Click here

  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. A01HTH4E02
      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
      E66-3 (+B) - Body ground Power switch on (IG) 11 to 14 V

    NG

    INSPECT RELAY (ENG W/PMP RELAY) Click here

    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
      E66-4 (PGND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    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
      E66-2 (NWP) - A25-28 (WPI) Always Below 1 Ω
      E66-1 (SWP) - A25-29 (WPO) Always Below 1 Ω
      E66-2 (NWP) or A25-28 (WPI) - Body ground Always 10 kΩ or higher
      E66-1 (SWP) or A25-29 (WPO) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    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 Techstream to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the Techstream on.

    4. Clear the DTCs Click here

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

    6. Turn the power switch on (IG).

    7. Turn the Techstream on.

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

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

    10. Read the DTCs.

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

    B

    END

    A

    REPLACE ECM Click here

  9. INSPECT RELAY (ENG W/PMP RELAY)


    1. A01HSSAE01

      Remove the ENG W/PMP 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

    REPLACE RELAY (ENG W/PMP RELAY)

    OK

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


    1. Remove the ENG W/PMP 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/PMP relay terminal 5 - E66-3 (+B) Always Below 1 Ω
      ENG W/PMP relay terminal 5 or E66-3 (+B) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  11. CHECK TERMINAL VOLTAGE (POWER SOURCE OF ENG W/PMP RELAY)


    1. A01HUNKE01
      Text in Illustration
      *1 Engine Room Relay Block and Junction Block Assembly
      *2 ENG W/PMP Relay

      Remove the ENG W/PMP 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/PMP relay terminal 3 - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  12. CHECK HARNESS AND CONNECTOR (ENG W/PMP RELAY - BODY GROUND)


    1. Remove the ENG W/PMP 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/PMP relay terminal 2 - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ENG W/PMP RELAY - EFI MAIN RELAY)