P261C

2ZR-FXE ENGINE CONTROL: SFI SYSTEM: P261B-P261D: Engine Coolant Pump "B" Control Malfunction
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.





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





TYPICAL ENABLING CONDITIONS

All





P261B: Engine Water Pump Circuit Performance





P261C and P261D: Engine Water Pump Circuit Range Check (Low Voltage, High Voltage)





TYPICAL MALFUNCTION THRESHOLDS

P261B: Engine Water Pump Circuit Performance





P261C: Engine Water Pump Circuit Range Check (Low Voltage)





P261D: Engine Water Pump Circuit Range Check (High Voltage)





COMPONENT OPERATING RANGE

P261B: Engine Water Pump Circuit Performance





P261C and P261D: Engine Water Pump Circuit Range Check (Low Voltage, High Voltage)





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) Reading and Clearing Diagnostic Trouble Codes.

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

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

6. Put the engine in inspection mode (maintenance mode) Component Tests and General Diagnostics.

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.

HINT
- 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.





HINT
- 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 Reading and Clearing Diagnostic Trouble Codes.

HINT
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.

WIRING DIAGRAM





INSPECTION PROCEDURE

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

HINT
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)

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

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

(e) 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 (ENGINE WATER PUMP ASSEMBLY)
OK -- Continue to next step.

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

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

(a) Disconnect the engine water pump assembly connector.

(b) Disconnect the ECM connector.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

3. CHECK ECM (WPI VOLTAGE)

(a) Disconnect the engine water pump assembly connector.





(b) Turn the power switch on (IG).

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

Standard Voltage:





Text in Illustration





NG -- REPLACE ECM Removal

OK -- REPLACE ENGINE WATER PUMP ASSEMBLY Removal

4. CHECK TERMINAL VOLTAGE (ENGINE WATER PUMP ASSEMBLY)

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

(a) Disconnect the engine water pump assembly connector.





(b) Turn the power switch on (IG).

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

Standard Voltage:





Text in Illustration





NG -- INSPECT ENG W/P RELAY
OK -- Continue to next step.

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

(a) Disconnect the engine water pump assembly connector.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

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

(a) Disconnect the engine water pump assembly connector.

(b) Disconnect the ECM connector.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

7. REPLACE ENGINE WATER PUMP ASSEMBLY

(a) Replace the engine water pump assembly Removal.

NEXT -- Continue to next step.

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

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(e) Drive the vehicle in accordance with the driving pattern described in the Confirmation Driving Pattern.

(f) Enter the following menus: Powertrain / Engine and ECT / Trouble codes.

(g) Read the DTCs.

Result





B -- END

A -- REPLACE ECM Removal

9. INSPECT ENG W/P RELAY

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





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

Standard Resistance:





NG -- REPLACE ENG W/P RELAY
OK -- Continue to next step.

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

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

(b) Disconnect the engine water pump assembly connector.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

11. CHECK ENG W/P RELAY (POWER SOURCE)

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





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

Standard Voltage:





Text in Illustration





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

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

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

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

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