DTC P023A-12: Charge Air Cooler Coolant Pump Control Circuit Short to Battery [10/2022 - 11/2023]: Procedure

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CHECK TERMINAL VOLTAGE (POWER SOURCE OF ELECTRIC WATER PUMP ASSEMBLY)

Disconnect the electric water pump assembly connector.
Turn the ignition switch to ON.

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

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*a	Front view of wire harness connector (to Electric Water Pump Assembly)

Standard Voltage

Tester Connection	Condition	Specified Condition
A85-3 (SWP) - Body ground	Ignition switch ON	Below 1 V

Result

Proceed to
OK
NG

Result:

See step 3

Result:

See step 2

INSPECT ECM (SWP TERMINAL)

Disconnect the electric water pump assembly connector.

Perform the Active Test using the GTS.

Powertrain > Engine > Active Test

Tester Display
Control the Intercooler Water Pump

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

Standard Resistance

Tester Connection	Condition	Specified Condition
A85-3 (SWP) - Body ground	Active Test OFF → ON	Active Test OFF: Resistance stabilized → ON: Resistance changes*

HINT:

*: The transistor inside the ECM performs duty control according to the Active Test being operated. The resistance of the SWP terminal changes while the Active Test is on due to duty control. If the resistance is stable while the Active Test is off and changes while the Active Test is on, the transistor is working correctly. If the transistor does not operate when the Active Test is on, there may be a malfunction in the ECM.

Result