DTC P0A94-553: DC / DC Converter Performance [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
P0A94-553 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
P0A1A (all INF codes)*1	Generator Control Module
P0A1B (all INF codes)*1	Drive Motor "A" Control Module
P0A1D (all INF codes)*1	Hybrid Powertrain Control Module
P0A3F-243	Drive Motor "A" Position Sensor Circuit
P0A40-500	Drive Motor "A" Position Sensor Circuit Range / Performance
P0A41-245	Drive Motor "A" Position Sensor Circuit Low
P0A4B-253	Generator Position Sensor Circuit
P0A4C-513	Generator Position Sensor Circuit Range / Performance
P0A4D-255	Generator Position Sensor Circuit Low
P0A60 (all INF codes)*1	Drive Motor "A" Phase V Current
P0A63 (all INF codes)*1	Drive Motor "A" Phase W Current
P0A72 (all INF codes)*1	Generator Phase V Current
P0A75 (all INF codes)*1	Generator Phase W Current
P0A78-113, 128, 266, 267, 279, 284, 286, 287, 306, 503, 504, 505, 506, 586, 806, 807, 808	Drive Motor "A" Inverter Performance
P0A7A-122, 130, 322, 324, 325, 344, 517, 518, 809, 810, 811	Generator Inverter Performance
P0A90-509	Drive Motor "A" Performance
P0A92-521	Hybrid Generator Performance
P0A94-442, 547, 548, 549, 554, 555, 556, 585, 587, 589, 590	DC / DC Converter Performance
P0C73-776	Motor Electronics Coolant Pump "A" Control Performance
P0C76-523	Hybrid Battery System Discharge Time Too Long
P314A-828	Inverter Coolant Pump Speed Signal

HINT:

*1: If any INF codes are output for this DTC, refer to the corresponding diagnostic procedure.
P0A94-553 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. After troubleshooting and repairing all output DTCs, be sure to replace the inverter with converter assembly.

Turn the power switch off.

B → See step 35

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 36

OK: Go to next step
CHECK HV COOLANT (CHECK FOR CONDITIONS THAT MAY HAVE CAUSED FREEZING). Refer to PROCEDURE - Step 16
B → See step 21

A: Go to next step
CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - GENERATOR RESOLVER). Refer to PROCEDURE - Step 3
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step
CHECK GENERATOR RESOLVER. Refer to PROCEDURE - Step 4
NG → See step 22

OK: Go to next step
CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - MOTOR RESOLVER). Refer to PROCEDURE - Step 5
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step
CHECK MOTOR RESOLVER. Refer to PROCEDURE - Step 6
NG → See step 24

OK: Go to next step
CHECK INVERTER WITH CONVERTER ASSEMBLY (GENERATOR CABLE CONNECTION CONDITION). Refer to PROCEDURE - Step 9
B → REPLACE MALFUNCTIONING PARTS

C → CONNECT SECURELY

A: Go to next step
CHECK INVERTER WITH CONVERTER ASSEMBLY (MOTOR CABLE CONNECTION CONDITION). Refer to PROCEDURE - Step 10
B → REPLACE MALFUNCTIONING PARTS

C → CONNECT SECURELY

A: Go to next step
CHECK HYBRID VEHICLE TRANSAXLE ASSEMBLY (MG1). Refer to PROCEDURE - Step 11
NG → See step 26

OK: Go to next step
CHECK HYBRID VEHICLE TRANSAXLE ASSEMBLY (MG2). Refer to PROCEDURE - Step 12
NG → See step 28

OK: Go to next step
CHECK FUSE (INV). Refer to PROCEDURE - Step 13
NG → See step 30

OK: Go to next step
CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY POWER SOURCE CIRCUIT). Refer to PROCEDURE - Step 14
NG → REPAIR OR REPLACE POWER SOURCE CIRCUIT

OK: Go to next step
CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - INVERTER WITH CONVERTER ASSEMBLY). Refer to PROCEDURE - Step 15
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step
CHECK POWER MANAGEMENT CONTROL ECU. Refer to PROCEDURE - Step 16
NG → See step 34

OK: Go to next step
CHECK CONNECTOR CONNECTION CONDITION (GENERATOR RESOLVER CONNECTOR). Refer to PROCEDURE - Step 7
NG → CONNECT SECURELY

OK: Go to next step
CHECK CONNECTOR CONNECTION CONDITION (MOTOR RESOLVER CONNECTOR). Refer to PROCEDURE - Step 8
NG → CONNECT SECURELY

OK → See step 33
REPLACE HV COOLANT. Refer to PROCEDURE - Step 7
NEXT → COMPLETED
CHECK CONNECTOR CONNECTION CONDITION (GENERATOR RESOLVER CONNECTOR). Refer to PROCEDURE - Step 9
NG → CONNECT SECURELY

OK: Go to next step
CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - GENERATOR RESOLVER). Refer to PROCEDURE - Step 10
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR

OK → See step 37
CHECK CONNECTOR CONNECTION CONDITION (MOTOR RESOLVER CONNECTOR). Refer to PROCEDURE - Step 11
NG → CONNECT SECURELY

OK: Go to next step
CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - MOTOR RESOLVER). Refer to PROCEDURE - Step 12
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR

OK → See step 37
CHECK HYBRID VEHICLE TRANSAXLE ASSEMBLY (GENERATOR CABLE CONNECTION CONDITION). Refer to PROCEDURE - Step 26
B → REPLACE MALFUNCTIONING PARTS

C → CONNECT SECURELY

A: Go to next step
CHECK GENERATOR CABLE. Refer to PROCEDURE - Step 27
NG → See step 38

OK → See step 37
CHECK HYBRID VEHICLE TRANSAXLE ASSEMBLY (MOTOR CABLE CONNECTION CONDITION). Refer to PROCEDURE - Step 28
B → REPLACE MALFUNCTIONING PARTS

C → CONNECT SECURELY

A: Go to next step
CHECK MOTOR CABLE. Refer to PROCEDURE - Step 29
NG → See step 39

OK → See step 37
CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - INV FUSE). Refer to PROCEDURE - Step 23
NG → See step 32

OK: Go to next step
REPLACE INVERTER WITH CONVERTER ASSEMBLY
Refer to COMPONENTS [08/2013 - ]

NEXT → REPLACE FUSE (INV)
REPAIR OR REPLACE HARNESS OR CONNECTOR
NEXT → REPLACE FUSE (INV)
REPLACE INVERTER WITH CONVERTER ASSEMBLY. Refer to COMPONENTS [08/2013 - ]
REPLACE POWER MANAGEMENT CONTROL ECU. Refer to COMPONENTS [08/2013 - ]
GO TO DTC CHART (HYBRID CONTROL SYSTEM). Refer to DIAGNOSTIC TROUBLE CODE CHART [08/2013 - ]
CHECK COOLING FAN SYSTEM. Refer to Cooling Fan Circuit [08/2013 - ]
REPLACE HYBRID VEHICLE TRANSAXLE ASSEMBLY. Refer to COMPONENTS [08/2013 - ]
REPLACE GENERATOR CABLE. Refer to COMPONENTS [08/2013 - ]
REPLACE MOTOR CABLE. Refer to COMPONENTS [08/2013 - ]