DTC P0C3E-628: DC / DC Converter Temperature Sensor "B" Range / Performance; DTC P0C41-627: DC / DC Converter Temperature Sensor "B" Intermittent / Erratic [08/2013 - ]: Procedure

WARNING: This page is about a different car, the 2014 Lexus ES 300h. However, it is still accessible from the selected car via links, so may be relevant.

CHECK DTC OUTPUT (HYBRID CONTROL)

Connect the Techstream to the DLC3.
Turn the power switch on (IG).
Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.

Check for DTCs.

Result

Result	Proceed to
P0C3E-628 or P0C41-627 only is output, or DTCs except the ones in the table below are also output.	A
Any of the following DTCs are also output.	B

DTC No.	Relevant Diagnosis
P0A93-346	Inverter Cooling System Performance
P0C73-776	Motor Electronics Coolant Pump "A" Control Performance
P314A-828	Inverter Coolant Pump Speed Signal

HINT:

P0C3E-628 or P0C41-627 may be stored due to a malfunction which also causes DTCs in the preceding table to be stored. In this case, first troubleshoot the output DTCs in the preceding table. Then, perform a test to attempt to reproduce the problems, and check that no DTCs are output.

Turn the power switch off.

B → See step 8

A: Go to next step

CHECK CONNECTOR CONNECTION CONDITION (INVERTER WITH CONVERTER ASSEMBLY CONNECTOR). Refer to PROCEDURE - Step 4
NG → CONNECT SECURELY

OK: Go to next step
CHECK QUANTITY OF HV COOLANT. Refer to PROCEDURE - Step 3
B → ADD HV COOLANT

C → INSPECT FOR HV COOLANT LEAK AND ADD HV COOLANT

A: Go to next step
CHECK COOLANT HOSE. Refer to PROCEDURE - Step 4
NG → CORRECT THE PROBLEM

OK: Go to next step
PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE ELECTRIC COOLING FAN). Refer to PROCEDURE - Step 5
NG → See step 10

OK: Go to next step
CHECK HV COOLANT (CHECK FOR CONDITIONS THAT MAY HAVE CAUSED FREEZING). Refer to PROCEDURE - Step 6
B → See step 9

A: Go to next step
REPLACE HV COOLANT. Refer to PROCEDURE - Step 7
NEXT → COMPLETED
GO TO DTC CHART (HYBRID CONTROL SYSTEM). Refer to DIAGNOSTIC TROUBLE CODE CHART [08/2013 - ]
REPLACE INVERTER WITH CONVERTER ASSEMBLY. Refer to COMPONENTS [08/2013 - ]
CHECK COOLING FAN SYSTEM. Refer to Cooling Fan Circuit [08/2013 - ]