DTC P0597-14: Thermostat Heater Control Circuit Short to Ground or Open [10/2017 - ]: Procedure
WARNING: This page does not describe the selected car, but rather 14 other vehicles, including the 2024 Lexus IS 350, 2024 Lexus IS 300, 2023 Lexus IS 350, 2023 Lexus IS 300, and 2022 Lexus IS 350. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK TERMINAL VOLTAGE (POWER SOURCE OF WATER INLET WITH THERMOSTAT SUB-ASSEMBLY)
*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 F115-1 (ETM+) - Body ground Engine switch on (IG) 11 to 14 V Result
Proceed to OK NG
Result:
NG
See step 6
Result:
OK
See step 2
- INSPECT WATER INLET WITH THERMOSTAT SUB-ASSEMBLY
- Inspect the water inlet with thermostat sub-assembly.
Refer to INSPECTION [10/2017 - ]
Result
Proceed to OK NG
Result:
NG
REPLACE WATER INLET WITH THERMOSTAT SUB-ASSEMBLY. Refer to REMOVAL [10/2017 - ]
Result:
OK
See step 3
- Inspect the water inlet with thermostat sub-assembly.
- 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 F115-2 (ETM-) - F102-64 (PTCR) Always Below 1 Ω F115-2 (ETM-) or F102-64 (PTCR) - Body ground and other terminals Always 10 kΩ or higher Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
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:
NEXT
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:
A
CHECK FOR INTERMITTENT PROBLEMS. Refer to CHECK FOR INTERMITTENT PROBLEMS [10/2017 - ]
Result:
B
REPLACE ECM. Refer to REMOVAL [10/2017 - ]
- CHECK HARNESS AND CONNECTOR (SEMICONDUCTOR POWER INTEGRATION ECU - WATER INLET WITH THERMOSTAT SUB-ASSEMBLY)
- Disconnect the semiconductor power integration ECU connector.
- Disconnect the water inlet with thermostat sub-assembly connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition 2G-2 - F115-1 (ETM+) Always Below 1 Ω 2G-2 or F115-1 (ETM+) - Body ground and other terminals Always 10 kΩ or higher Result
Proceed to OK NG
Result:
OK
REPLACE SEMICONDUCTOR POWER INTEGRATION ECU. Refer to REMOVAL [04/2013 - ]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR