Toyota Corolla Cross Owners & Service Manuals

Toyota Corolla Cross: Engine Coolant Pump Circuit Short to Ground or Open (P26CA14)

Toyota Corolla Cross (2022-2024) Service Manual / Engine & Hybrid System / M20a-fks (engine Control) / Sfi System / Engine Coolant Pump Circuit Short to Ground or Open (P26CA14)

DESCRIPTION

Refer to DTC P26CA12.

Click here

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Note

P26CA14

Engine Coolant Pump Circuit Short to Ground or Open

The operation duty ratio (WPO) of the monitoring engine water pump assembly becomes a certain amount or less when engine water pump assembly operation command is output (1 trip detection logic).

  • Open or short in engine water pump assembly (water inlet housing) circuit
  • Engine water pump assembly (water inlet housing)
  • ECM

Comes on

  • SAE Code: P26CC
  • DTC for Mexico Models: Applies
Related Data List

DTC No.

Data List

P26CA14

  • Coolant Temperature
  • Electric Water Pump Target Speed
  • Electric Water Pump Speed

MONITOR DESCRIPTION

The ECM outputs an operation duty signal (WPO) to steplessly control the speed of the engine water pump assembly. The ECM outputs an operation duty signal (WPO) to the engine water pump assembly and monitors the actual duty signal (WPO) being output. When the operation duty signal (WPO) is being output to the to the engine water pump assembly and the actual operation duty signal (WPO) is a certain value or less, the ECM detects a malfunction and stores a DTC.

MONITOR STRATEGY

Related DTCs

P26CC: Engine water pump circuit range check (Low voltage)

Required Sensors/Components (Main)

Engine water pump assembly

Required Sensors/Components (Related)

-

Frequency of Operation

Continuous

Duration

3 seconds

MIL Operation

Immediate

Sequence of Operation

None

TYPICAL ENABLING CONDITIONS

All of the following conditions are met

-

Auxiliary battery voltage

8 V or higher

Ignition switch

ON

Time after ignition switch off to ON

0.5 seconds or more

Output duty cycle

30 to 85%

Starter

Off

Engine water pump circuit pulse input fail (P26CA)

Not detected

TYPICAL MALFUNCTION THRESHOLDS

Both of the following conditions are met

-

Engine water pump assembly output terminal voltage level

Low

Engine water pump assembly output signal

No signal

CONFIRMATION DRIVING PATTERN

HINT:

  • After repair has been completed, clear the DTC and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.

    Click here

  • When clearing the permanent DTCs, refer to the "CLEAR PERMANENT DTC" procedure.

    Click here

  1. Connect the GTS to the DLC3.
  2. Turn the ignition switch to ON.
  3. Turn the GTS on.
  4. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
  5. Turn the ignition switch off and wait for at least 30 seconds.
  6. Turn the ignition switch to ON [A].
  7. Turn the GTS on.
  8. Move the shift lever to P [B].
  9. Start the engine and maintain the engine speed at 2500 rpm or more for at least 40 seconds [C].
  10. Enter the following menus: Powertrain / Engine / Trouble Codes [D].
  11. 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.
  12. Enter the following menus: Powertrain / Engine / Utility / All Readiness.
  13. Input the DTC: P26CA14.
  14. Check the DTC judgment result.

    GTS 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

    HINT:

    • If the judgment result is NORMAL, the system is normal.
    • If the judgment result is ABNORMAL, the system has a malfunction.
    • If the judgment result is INCOMPLETE, perform steps [B] through [D] again.
    • [A] to [D]: Normal judgment procedure.

      The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.

    • When clearing the permanent DTCs, do not disconnect the cable from the auxiliary battery terminal or attempt to clear the DTCs during this procedure, as doing so will clear the universal trip and normal judgment histories.

WIRING DIAGRAM

Refer to DTC P26CA12.

Click here

CAUTION / NOTICE / HINT

NOTICE:

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

HINT:

Read Freeze Frame Data using the GTS. 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.

INSPECT ECM (INTERNAL CIRCUIT)

*a

Front view of wire harness connector

(to Engine Water Pump Assembly (Water Inlet Housing))

(a) Disconnect the engine water pump assembly (water inlet housing) connector.

(b) Turn the ignition switch to ON.

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

Standard:

Tester Connection

Condition

Specified Condition

C131-3 (SWP) - Body ground

Ignition switch ON

Resistance fluctuates*

HINT:

  • *: When the connector of the engine water pump assembly is disconnected, the ECM will enter fail-safe mode. When the ECM is in fail-safe mode, a continuous duty signal will be output and the resistance will fluctuate as the transistor inside the ECM is turned on an off.
  • If the resistance fluctuates while the ECM is in fail-safe mode after the connector of the engine water pump assembly is disconnected, it can be determined that the transistor is operating.
  • If the transistor does not operate, the ECM may be malfunctioning.
  • If the resistance fluctuates after turning the ignition switch to ON, it can be determined that the ECM is in fail-safe mode.
NG

REPLACE ECM

OK

2.

CHECK HARNESS AND CONNECTOR (ENGINE WATER PUMP ASSEMBLY (WATER INLET HOUSING) - ECM)

(a) Disconnect the engine water pump assembly (water inlet housing) connector.

(b) Disconnect the ECM connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

C131-3 (SWP) - C76-50 (WPO)

Always

Below 1 Ω

C131-3 (SWP) or C76-50 (WPO) - Body ground

Always

10 kΩ or higher

OK

REPLACE ENGINE WATER PUMP ASSEMBLY (WATER INLET HOUSING)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

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