Lexus NX: Lost Communication with Drive Motor Control Module "A" (U0110-159,U0110-656,U0110-657)

Lexus NX Service Manual / Engine & Hybrid System / 2ar-fxe (hybrid / Battery Control) / Hybrid Control System / Lost Communication with Drive Motor Control Module "A" (U0110-159,U0110-656,U0110-657)

DESCRIPTION

For a description of the inverter.

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The MG ECU, which is built into in the inverter with converter assembly, controls motor (MG2) based on commands from the hybrid vehicle control ECU. The MG ECU monitors communication data and detects malfunctions.

The hybrid vehicle control ECU monitors communication data and detects malfunctions.

A communication error between the MG ECU and hybrid vehicle control ECU.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Warning Indicate
U0110-159	Lost Communication with Drive Motor Control Module "A"	Error in reception from inverter with converter assembly (MG ECU) via serial communication (out of communication standard) (1 trip detection logic)	Wire harness or connector Inverter with converter assembly Hybrid vehicle transaxle assembly Hybrid vehicle control ECU PCU fuse	Does not come on	Master Warning Light: Comes on
U0110-656	Lost Communication with Drive Motor Control Module "A"	Error in reception from inverter with converter assembly (MG ECU) via serial communication (out of communication standard) (1 trip detection logic)	Wire harness or connector Inverter with converter assembly Hybrid vehicle transaxle assembly Hybrid vehicle control ECU PCU fuse	Does not come on	Master Warning Light: Comes on
U0110-657	Lost Communication with Drive Motor Control Module "A"	Error in reception from inverter with converter assembly (MG ECU) via serial communication (no reception) (1 trip detection logic)	Wire harness or connector Inverter with converter assembly Hybrid vehicle transaxle assembly Hybrid vehicle control ECU PCU fuse	Does not come on	Master Warning Light: Comes on

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Warning Indicate

U0110-159

Lost Communication with Drive Motor Control Module "A"

Error in reception from inverter with converter assembly (MG ECU) via serial communication (out of communication standard)

(1 trip detection logic)

Wire harness or connector
Inverter with converter assembly
Hybrid vehicle transaxle assembly
Hybrid vehicle control ECU
PCU fuse

Does not come on

Master Warning Light:

Comes on

U0110-656

Lost Communication with Drive Motor Control Module "A"

Error in reception from inverter with converter assembly (MG ECU) via serial communication (out of communication standard)

(1 trip detection logic)

Wire harness or connector
Inverter with converter assembly
Hybrid vehicle transaxle assembly
Hybrid vehicle control ECU
PCU fuse

Does not come on

Master Warning Light:

Comes on

U0110-657

Lost Communication with Drive Motor Control Module "A"

Error in reception from inverter with converter assembly (MG ECU) via serial communication (no reception)

(1 trip detection logic)

Wire harness or connector
Inverter with converter assembly
Hybrid vehicle transaxle assembly
Hybrid vehicle control ECU
PCU fuse

Does not come on

Master Warning Light:

Comes on

WIRING DIAGRAM

Refer to the wiring diagram for the inverter low-voltage circuit.

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Refer to the wiring diagram for DTC P0AA6-526.

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CAUTION / NOTICE / HINT

CAUTION:

Before inspecting the high-voltage system or disconnecting the low voltage connector of the inverter with converter assembly, take safety precautions such as wearing insulated gloves and removing the service plug grip to prevent electrical shocks. After removing the service plug grip, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system.
After removing the service plug grip, wait for at least 10 minutes before touching any of the high-voltage connectors or terminals. After waiting for 10 minutes, check the voltage at the terminals in the inspection point in the inverter with converter assembly. The voltage should be 0 V before beginning work.
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HINT:

Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.

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.
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If DTCs U0110-159, U0110-656, and/or U0110-657 were stored due to incomplete engagement of the connectors, and the system returns to normal when the power switch is turned on (IG) after clearing the DTCs, DTC P324E-788 will be stored. Proceed to troubleshooting without considering DTC P324E-788.

HINT:

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

Turn the power switch on (IG) and wait for 2 minutes or more.

PROCEDURE

1.	INSPECT FUSE (PCU)

(a) Remove the PCU fuse from the No. 1 engine room relay block.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
PCU fuse terminals	Always	Below 1 Ω

*1	No. 1 Engine Room Relay Block
*2	PCU Fuse

GO TO STEP 12

CLEAR DTC

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3.	CHECK DTC OUTPUT (HYBRID CONTROL)

(a) Connect the Techstream to the DLC3.

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

(d) Check for DTCs.

Powertrain > Hybrid Control > Trouble Codes

(e) Turn the power switch off.

U0110-159, 656 and 657 are not output.

CHECK FOR INTERMITTENT PROBLEMS

U0110-159, 656 or 657 is output.

4.	CHECK INVERTER WITH CONVERTER ASSEMBLY (GENERATOR CABLE CONNECTION CONDITION)

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Result		Proceed to
The terminals are connected securely and there are no contact problems.	There are no arc marks.	A
The terminals are not connected securely and there is a contact problem.	There are arc marks.	B
The terminals are not connected securely and there is a contact problem.	There are no arc marks.	C
The terminals are connected securely and there are no contact problems.	There are arc marks.	B

REPLACE MALFUNCTIONING PARTS

CONNECT SECURELY

5.	CHECK INVERTER WITH CONVERTER ASSEMBLY (MOTOR CABLE CONNECTION CONDITION)

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Result		Proceed to
The terminals are connected securely and there are no contact problems.	There are no arc marks.	A
The terminals are not connected securely and there is a contact problem.	There are arc marks.	B
The terminals are not connected securely and there is a contact problem.	There are no arc marks.	C
The terminals are connected securely and there are no contact problems.	There are arc marks.	B

REPLACE MALFUNCTIONING PARTS

CONNECT SECURELY

6.	CHECK HYBRID VEHICLE TRANSAXLE ASSEMBLY (GENERATOR (MG1))

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REPLACE HYBRID VEHICLE TRANSAXLE ASSEMBLY

7.	CHECK HYBRID VEHICLE TRANSAXLE ASSEMBLY (MOTOR (MG2))

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REPLACE HYBRID VEHICLE TRANSAXLE ASSEMBLY

8.	CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY POWER SOURCE CIRCUIT)

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.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A58-10 (GND1) - Body ground	Power switch off	Below 1 Ω
A58-11 (GND2) - Body ground	Power switch off	Below 1 Ω

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

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

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

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
A58-30 (+B) - Body ground	Power switch on (IG)	11 to 14 V
A58-31 (+B2) - Body ground	Power switch on (IG)	11 to 14 V

NOTICE:

Turning the power switch on (IG) with the inverter with converter assembly disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.

(g) Turn the power switch off.

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

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

REPAIR OR REPLACE HARNESS OR CONNECTOR

9.	CHECK HYBRID VEHICLE CONTROL ECU (CHECK WAVEFORM)

(a) Connect an oscilloscope between the hybrid vehicle control ECU terminals specified in the following table.

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

Item

Contents

Tester Connection

CH1: A61-33 (CLK+) - I115-6 (E1)

CH2: A61-32 (CLK-) - I115-6 (E1)

Equipment Setting

1 V/DIV., 1 μs./DIV.

Condition

Power switch on (IG)

HINT:

Inspect with the connector connected.
If pulses are generated, the shape of the waveform can be assumed to be normal.
The shape of the waveform may vary according to communication conditions.

*a	Component with harness connected (Hybrid Vehicle Control ECU)

(d) Turn the power switch off.

The waveform differs from the one shown in the illustration.

GO TO STEP 13

The waveform appears as shown in the illustration.

10.	CHECK HYBRID VEHICLE CONTROL ECU (CHECK WAVEFORM)

(a) Connect an oscilloscope between the hybrid vehicle control ECU terminals specified in the following table.

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

Item

Contents

Tester Connection

CH1: A61-31 (REQ+) - I115-6 (E1)

CH2: A61-30 (REQ-) - I115-6 (E1)

Equipment Setting

1 V/DIV., 1 ms./DIV.

Condition

Power switch on (IG)

HINT:

Inspect with the connector connected.
If pulses are generated, the shape of the waveform can be assumed to be normal.
The shape of the waveform may vary according to communication conditions.

*a	Component with harness connected (Hybrid Vehicle Control ECU)

(d) Turn the power switch off.

The waveform differs from the one shown in the illustration.

GO TO STEP 15

The waveform appears as shown in the illustration.

11.	CHECK HYBRID VEHICLE CONTROL ECU (CHECK WAVEFORM)

(a) Connect an oscilloscope between the hybrid vehicle control ECU terminals specified in the following table.

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

Item

Contents

Tester Connection

CH1: A61-23 (MTH+) - I115-6 (E1)

CH2: A61-22 (MTH-) - I115-6 (E1)

Equipment Setting

1 V/DIV., 200 μs./DIV.

Condition

Power switch on (IG)

HINT:

Inspect with the connector connected.
If pulses are generated, the shape of the waveform can be assumed to be normal.
The shape of the waveform may vary according to communication conditions.

*a	Component with harness connected (Hybrid Vehicle Control ECU)

(d) Turn the power switch off.

The waveform appears as shown in the illustration.

REPLACE HYBRID VEHICLE CONTROL ECU

The waveform differs from the one shown in the illustration.

GO TO STEP 17

12.	REPLACE FUSE (PCU)

(a) Replace the PCU fuse.

*1	No. 1 Engine Room Relay Block
*2	PCU Fuse

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

OK:

There is no open circuit in the PCU fuse.

HINT:

If the fuse does not become open again after turning the power switch on (READY), it can be assumed that the previous fuse failed due to age.

(d) Turn the power switch off.

COMPLETED

GO TO STEP 19

13.	CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - INVERTER WITH CONVERTER 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) Disconnect the A61 hybrid vehicle control ECU connector.

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

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

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
A61-33 (CLK+) - Body ground	Power switch on (IG)	Below 1 V
A61-32 (CLK-) - Body ground	Power switch on (IG)	Below 1 V

NOTICE:

Turning the power switch on (IG) with the hybrid vehicle control ECU connector and the inverter with converter assembly disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.

Rear view of wire harness connector

(to Hybrid Vehicle Control ECU)

Front view of wire harness connector

(to Inverter with Converter Assembly)

(g) Turn the power switch off.

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

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

Standard Resistance (Check for Open):

Tester Connection	Condition	Specified Condition
A61-33 (CLK+) - A58-7 (CLK+)	Power switch off	Below 1 Ω
A61-32 (CLK-) - A58-18 (CLK-)	Power switch off	Below 1 Ω

Standard Resistance (Check for Short):

Tester Connection	Condition	Specified Condition
A61-33 (CLK+) or A58-7 (CLK+) - Body ground and other terminals	Power switch off	10 kΩ or higher
A61-32 (CLK-) or A58-18 (CLK-) - Body ground and other terminals	Power switch off	10 kΩ or higher

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

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

REPAIR OR REPLACE HARNESS OR CONNECTOR

14.	CHECK INVERTER WITH CONVERTER ASSEMBLY

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

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A61-33 (CLK+) - A61-32 (CLK-)	Power switch off	80 to 170 Ω

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

REPLACE HYBRID VEHICLE CONTROL ECU

REPLACE INVERTER WITH CONVERTER ASSEMBLY

15.	CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - INVERTER WITH CONVERTER 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) Disconnect the A61 hybrid vehicle control ECU connector.

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

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

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
A61-31 (REQ+) - Body ground	Power switch on (IG)	Below 1 V
A61-30(REQ-) - Body ground	Power switch on (IG)	Below 1 V

NOTICE:

Rear view of wire harness connector

(to Hybrid Vehicle Control ECU)

Front view of wire harness connector

(to Inverter with Converter Assembly)

(g) Turn the power switch off.

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

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

Standard Resistance (Check for Open):

Tester Connection	Condition	Specified Condition
A61-31 (REQ+) - A58-26 (REQ+)	Power switch off	Below 1 Ω
A61-30(REQ-) - A58-37 (REQ-)	Power switch off	Below 1 Ω

Standard Resistance (Check for Short):

Tester Connection	Condition	Specified Condition
A61-31 (REQ+) or A58-26 (REQ+) - Body ground and other terminals	Power switch off	10 kΩ or higher
A61-30(REQ-) or A58-37 (REQ-) - Body ground and other terminals	Power switch off	10 kΩ or higher

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

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

REPAIR OR REPLACE HARNESS OR CONNECTOR

16.	CHECK INVERTER WITH CONVERTER ASSEMBLY

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

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A61-31 (REQ+) - A61-30 (REQ-)	Power switch off	80 to 170 Ω

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

REPLACE HYBRID VEHICLE CONTROL ECU

REPLACE INVERTER WITH CONVERTER ASSEMBLY

17.	CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - INVERTER WITH CONVERTER 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) Disconnect the A61 hybrid vehicle control ECU connector.

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

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

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
A61-23 (MTH+) - Body ground	Power switch on (IG)	Below 1 V
A61-22 (MTH-) - Body ground	Power switch on (IG)	Below 1 V

NOTICE:

Rear view of wire harness connector

(to Hybrid Vehicle Control ECU)

Front view of wire harness connector

(to Inverter with Converter Assembly)

(g) Turn the power switch off.

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

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

Standard Resistance (Check for Open):

Tester Connection	Condition	Specified Condition
A61-23 (MTH+) - A58-8 (MTH+)	Power switch off	Below 1 Ω
A61-22 (MTH-) - A58-19 (MTH-)	Power switch off	Below 1 Ω

Standard Resistance (Check for Short):

Tester Connection	Condition	Specified Condition
A61-23 (MTH+) or A58-8 (MTH+) - Body ground and other terminals	Power switch off	10 kΩ or higher
A61-22 (MTH-) or A58-19 (MTH-) - Body ground and other terminals	Power switch off	10 kΩ or higher

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

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

REPAIR OR REPLACE HARNESS OR CONNECTOR

18.	CHECK INVERTER WITH CONVERTER 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) Disconnect the A58 inverter with converter assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A61-23 (MTH+) -A61-22 (MTH-)	Power switch off	80 to 170 Ω

*a	Component with harness connected (Hybrid Vehicle Control ECU)

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

REPLACE INVERTER WITH CONVERTER ASSEMBLY

REPLACE HYBRID VEHICLE CONTROL ECU

19.	CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - NO. 1 ENGINE ROOM RELAY BLOCK)

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 PCU fuse from the No. 1 engine room relay block.

Click here

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

No. 1 Engine Room Relay Block

PCU Fuse

Front view of wire harness connector

(to Inverter with Converter Assembly)

Standard Resistance (Check for Short):

Tester Connection	Condition	Specified Condition
A58-30 (+B), A58-31 (+B2) or 2 (PCU fuse terminal) - Body ground and other terminals	Power switch off	10 kΩ or higher

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

(f) Install the PCU fuse.

GO TO STEP 21

20.	REPLACE INVERTER WITH CONVERTER ASSEMBLY

Click here

REPLACE FUSE (PCU)

21.	REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE FUSE (PCU)

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