Lexus NX: High Voltage System Inter-Lock Circuit High (P0A0D-350,P0A0D-351)

DTC SUMMARY

MALFUNCTION DESCRIPTION

The hybrid vehicle control ECU detects that a safety device (interlock) is operated or that there is an open circuit in the detection circuit. (Even if an open circuit occurs while the vehicle is stopped, the system determines that the safety device was operated.)

The cause of this malfunction may be one of the following:

INSPECTION DESCRIPTION

System Diagram Location	Inspection Content	Reason	Inspection Step
*a	Check whether the safety device (interlock) is connected securely and installed properly (service plug grip, inverter upper cover or connector cover assembly, etc.). Hybrid vehicle control ECU or inverter connector	DTC output due to improper connection or forgetting to install parts.	4 to 9
*b	Inspect the detection circuit.	DTC output due to an open circuit or improper connection (dirt, foreign matter, etc.).	10 to 20

DESCRIPTION

When the hybrid vehicle control ECU detects that a safety device (interlock) is operated, such as when the service plug grip, inverter cover UPR or connector cover assembly is removed, it will prohibit hybrid system operation or shut off the system main relay. The 3 safety devices are located as follows; 1 in the service plug grip, 1 on the No. 2 frame wire that is connected to the inverter with converter assembly, 1 on the inverter cover UPR where the motor and generator cables, No. 2 frame wire and engine wire (air conditioning harness) are connected to the inverter with converter assembly. If the service plug grip, inverter cover UPR, or No. 2 frame wire is removed, the interlock signal line will be open. If the vehicle is being driven, this condition will be determined to be an open circuit and the system main relays will not be shut off. When the safety devices are re-installed correctly, the system will return to normal when the power switch is turned on (IG).

The system main relay will be turned off from the next trip after the open is detected until the condition returns to normal.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Warning Indicate
P0A0D-350	High Voltage System Inter-Lock Circuit High	Either of the following conditions is met: With the vehicle stopped, the service plug grip, connector cover assembly, inverter cover UPR or No. 2 frame wire with a safety device was removed. With the vehicle stopped, the interlock signal line became open. (1 trip detection logic)	Wire harness or connector Hybrid vehicle control ECU Service plug grip Inverter with converter assembly Connector cover assembly Inverter cover UPR No. 2 frame wire	Does not come on	Master Warning Light: Comes on
P0A0D-351	High Voltage System Inter-Lock Circuit High	Interlock signal line opens while the vehicle is being driven (at 5 km/h (3 mph) or more) (1 trip detection logic)	Wire harness or connector Hybrid vehicle control ECU Service plug grip Inverter with converter assembly Connector cover assembly Inverter cover UPR No. 2 frame wire	Does not come on	Master Warning Light: Comes on

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work.

Click here

HINT:

After the repair, clear the DTCs and perform the following procedure to check that DTCs are not output.

PROCEDURE

1.	CHECK DTC OUTPUT (HYBRID CONTROL)

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.

(d) Check for DTCs.

Powertrain > Hybrid Control > Trouble Codes

(e) Turn the power switch off.

P0A1D is output.

GO TO DTC CHART (P0A1D)

P0A0D only is output.

2.

CLEAR DTC

Click here

NEXT

3.	CHECK DTC OUTPUT (HYBRID CONTROL)

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.

(d) Check if DTCs are output.

Powertrain > Hybrid Control > Trouble Codes

(e) Turn the power switch off.

Neither P0A0D-350 or P0A0D-351 is output again.

GO TO STEP 13

P0A0D-350 or P0A0D-351 is output again.

4.	CHECK SERVICE PLUG GRIP

CAUTION:

Be sure to wear insulated gloves.

(a) Check if the service plug grip is installed correctly. Standard: "UNLOCK" is hidden and is not visible. NOTICE: Insert the service plug grip until a click sound is heard. If "UNLOCK" is printed on the service plug grip, push in the service plug grip until "UNLOCK" is not visible at all. HINT: For the removal and installation procedures. Click here P0A0D-350 is also set if the power switch is turned on (IG) with the service plug grip removed. Confirm the conditions when the malfunction occurred.

*1 Service Plug Grip

NG

INSTALL PARTS CORRECTLY

OK

5.	CHECK CONNECTOR CONNECTION CONDITION (HYBRID VEHICLE CONTROL ECU CONNECTOR)

Click here

NG

CONNECT SECURELY

OK

6.	CHECK CONNECTOR CONNECTION CONDITION (INVERTER WITH CONVERTER ASSEMBLY CONNECTOR)

Click here

Result	Proceed to
OK	A
NG (The connector is not connected securely.)	B
NG (The terminals are not making secure contact or are deformed, or water or foreign matter exists in the connector.)	C

B

CONNECT SECURELY

C

REPAIR OR REPLACE HARNESS OR CONNECTOR

A

7.	CHECK INVERTER COVER UPR

CAUTION:

Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:

After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Check if the inverter cover UPR of the inverter with converter assembly is installed correctly. OK: The inverter cover UPR is installed correctly.

NG

INSTALL PARTS CORRECTLY

OK

8.	CHECK CONNECTOR COVER ASSEMBLY

CAUTION:

Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:

After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Check if the connector cover assembly is connected correctly. OK: The connector cover assembly is connected correctly.

NG

INSTALL PARTS CORRECTLY

OK

9.	CHECK HARNESS AND CONNECTOR (AIR CONDITIONING HARNESS)

CAUTION:

Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:

After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Check if the air conditioner harness is connected correctly. OK: The air conditioner harness is connected correctly.

NG

INSTALL PARTS CORRECTLY

OK

10.	CHECK HYBRID VEHICLE CONTROL ECU

CAUTION:

Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:

After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Disconnect the A58 inverter with converter assembly connector.

Click here

(c) Connect the cable to the negative (-) auxiliary battery terminal.

(d) Turn the power switch on (IG).

(e) Measure the voltage according to the value(s) in the table below. Standard Voltage: Tester Connection Condition Specified Condition A58-16 (ILKI) - Body ground Power switch on (IG) 11 to 14 V NOTICE: Turning the power switch on (IG) with the inverter with converter assembly connector disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.

*a Front view of wire harness connector (to Inverter with Converter Assembly)

(f) Turn the power switch off.

(g) Disconnect the cable from the negative (-) auxiliary battery terminal.

(h) Reconnect the A58 inverter with converter assembly connector.

NG

GO TO STEP 14

OK

11.	CHECK INVERTER WITH CONVERTER ASSEMBLY (INTERLOCK)

CAUTION:

Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:

After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Disconnect the A58 inverter with converter assembly connector.

(c) Measure the resistance according to the value(s) in the table below. Standard Resistance: Tester Connection Condition Specified Condition A58-16 (ILKI) - A58-5 (ILKO) Power switch off Less than 10 Ω NOTICE: Do not remove the connector cover assembly, inverter cover UPR and air conditioner harness.

*a Component without harness connected (Inverter with Converter Assembly)

(d) Reconnect the A58 inverter with converter assembly connector.

NG

GO TO STEP 15

OK

12.	CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - BODY GROUND)

CAUTION:

Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:

After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Disconnect the A58 inverter with converter assembly connector.

(c) Install the service plug grip.

(d) Measure the resistance according to the value(s) in the table below. Standard Resistance: Tester Connection Condition Specified Condition A58-5 (ILKO) - Body ground Power switch off Below 1 Ω

*a Front view of wire harness connector (to Inverter with Converter Assembly)

(e) Remove the service plug grip.

(f) Reconnect the A58 inverter with converter assembly connector.

NG

GO TO STEP 18

OK

13.	CHECK CONNECTOR CONNECTION CONDITION (INTERLOCK CIRCUIT)

(a) Check the connections of each connector.

OK:

Dirt or foreign matter has not entered the connectors, and there is no evidence of contamination.

OK

REPLACE HYBRID VEHICLE CONTROL ECU

NG

REPAIR OR REPLACE CONNECTOR

14.	CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - HYBRID VEHICLE CONTROL ECU)

CAUTION:

Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:

After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Disconnect the A58 inverter with converter assembly connector.

(c) Disconnect the A61 hybrid vehicle control ECU connector.

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

*a

Front view of wire harness connector (to Inverter with Converter Assembly)

*b

Rear view of wire harness connector (to Hybrid Vehicle Control ECU)

Standard Resistance:

Tester Connection	Condition	Specified Condition
A58-16 (ILKI) - A61-13 (ILK)	Power switch off	Below 1 Ω

(e) Reconnect the A61 hybrid vehicle control ECU connector.

(f) Reconnect the A58 inverter with converter assembly connector.

OK

REPLACE HYBRID VEHICLE CONTROL ECU

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

15.	CHECK INVERTER COVER UPR

CAUTION:

Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:

After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Remove the inverter cover UPR from the inverter with converter assembly.

(c) Check the condition of the inverter cover UPR interlock. OK: Dirt or foreign matter has not entered the connectors, and there is no evidence of contamination.

*1 Inverter Cover UPR

(d) Install the inverter cover UPR.

NG

REPLACE INVERTER COVER UPR

OK

16.	CHECK CONNECTOR COVER ASSEMBLY

CAUTION:

Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:

After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Remove the connector cover assembly from the inverter with converter assembly.

(c) Check the condition of the connector cover assembly interlock. OK: Dirt or foreign objects have not entered the connection, and there is no evidence of contamination. HINT: The connector cover assembly is not available as a supply part. If it requires replacement, replace the inverter with converter assembly.

*1 Connector Cover Assembly

(d) Install the connector cover assembly from the inverter with converter assembly.

NG

REPLACE INVERTER WITH CONVERTER ASSEMBLY

OK

17.	CHECK HARNESS AND CONNECTOR (AIR CONDITIONING HARNESS CONNECTOR)

CAUTION:

Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:

After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Disconnect the air conditioning harness from the inverter with converter assembly.

(c) Check the air conditioning harness interlock. OK: Dirt or foreign matter has not entered the connectors, and there is no evidence of contamination.

*1 Air Conditioning Harness

(d) Connect the air conditioning harness to the inverter with converter assembly.

OK

REPLACE INVERTER WITH CONVERTER ASSEMBLY

NG

REPLACE AIR CONDITIONING HARNESS ASSEMBLY

18.	CHECK SERVICE PLUG GRIP

(a) Remove the service plug grip.

Click here

(b) Check the condition of the service plug grip interlock. OK: Dirt or foreign matter has not entered the connectors, and there is no evidence of contamination.

*1 Service Plug Grip

NG

REPLACE SERVICE PLUG GRIP

OK

19.	CHECK CONNECTOR CONNECTION CONDITION (INTERLOCK CONNECTOR)

CAUTION:

Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:

After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Check that the interlock connector at the service plug grip installation socket is connected correctly. OK: The connector is connected correctly.

*1 Interlock Connector

NG

INSTALL PARTS CORRECTLY

OK

20.	CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - SERVICE PLUG GRIP)

CAUTION:

Be sure to wear insulated gloves.

(a) Check that the service plug grip is not installed.

NOTICE:

After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Disconnect the A58 inverter with converter assembly connector.

(c) Disconnect the P31 service plug grip connector.

(d) Measure the resistance according to the value(s) in the table below. Standard Resistance: Tester Connection Condition Specified Condition A58-5 (ILKO) - P31-1 (ILK) Power switch off Below 1 Ω

*a Front view of wire harness connector (to Inverter with Converter Assembly) *b Rear view of wire harness connector (to Service Plug Grip)

(e) Reconnect the P31 service plug grip connector.

(f) Reconnect the A58 inverter with converter assembly connector.

OK

REPAIR OR REPLACE HARNESS OR CONNECTOR (SERVICE PLUG GRIP - BODY GROUND)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - SERVICE PLUG GRIP)

READ NEXT: