DTC P0597-14: Thermostat Heater Control Circuit Short to Ground or Open [06/2018 - 08/2021]: Procedure

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CHECK TERMINAL VOLTAGE (POWER SOURCE OF WATER INLET WITH THERMOSTAT SUB-ASSEMBLY)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*a	Front view of wire harness connector (to Water Inlet with Thermostat Sub-assembly)

Disconnect the water inlet with thermostat sub-assembly connector.
Turn the engine switch on (IG).

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

Standard Voltage

Tester Connection	Condition	Specified Condition
C25-1 (ETM+) - Body ground	Engine switch on (IG)	11 to 14 V

Result

Proceed to
OK
NG

Result:

REPAIR OR REPLACE HARNESS OR CONNECTOR (EFI-MAIN NO. 1 RELAY - WATER INLET WITH THERMOSTAT SUB-ASSEMBLY)

Result:

See step 2

INSPECT WATER INLET WITH THERMOSTAT SUB-ASSEMBLY

Inspect the water inlet with thermostat sub-assembly.

Refer to INSPECTION [06/2018 - ]

Result

Proceed to
OK
NG

Result:

REPLACE WATER INLET WITH THERMOSTAT SUB-ASSEMBLY. Refer to REMOVAL [06/2018 - 10/2019] , or refer to REMOVAL [10/2019 - 08/2021]

Result:

See step 3

CHECK HARNESS AND CONNECTOR (WATER INLET WITH THERMOSTAT SUB-ASSEMBLY - ECM)

Disconnect the water inlet with thermostat sub-assembly connector.
Disconnect the ECM connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
C25-2 (ETM-) - C32-64 (PTCR)	Always	Below 1 Ω
C25-2 (ETM-) or C32-64 (PTCR) - Body ground and other terminals	Always	10 kΩ or higher

Result

Proceed to
OK
NG

Result:

REPAIR OR REPLACE HARNESS OR CONNECTOR

Result:

See step 4

CLEAR DTC

Connect the Techstream to the DLC3.
Turn the engine switch on (IG).
Turn the Techstream on.
Clear the DTC.
Powertrain > Engine > Clear DTCs

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

Result

Proceed to
NEXT

Result:

See step 5

CHECK WHETHER DTC OUTPUT RECURS (DTC P0597-14)

Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine / Trouble Codes.

Read the DTCs.

Powertrain > Engine > Trouble Codes

Result

Result	Proceed to
DTCs are not output	A
DTC P0597-14 is output	B

Result:

CHECK FOR INTERMITTENT PROBLEMS. Refer to CHECK FOR INTERMITTENT PROBLEMS [06/2018 - ]

Result:

REPLACE ECM. Refer to REMOVAL [06/2018 - 10/2019] , or refer to REMOVAL [10/2019 - 08/2021]