Lexus NX: Skid Control ECU Communication Stop Mode

Lexus NX Service Manual / Power Source & Network / Networking / Can Communication System / Skid Control ECU Communication Stop Mode

DESCRIPTION

Detection Item

Symptom

Trouble Area

Skid Control ECU Communication Stop Mode

Any of the following conditions are met:

  • Communication stop for "Skid Control (ABS/VSC/TRAC)" is indicated on "Communication Bus Check".

    Click here

  • Communication system DTCs (DTCs that start with U) that are output correspond to "Skid Control ECU Communication Stop Mode" in "DTC Combination Table".

    Click here

  • Brake booster with master cylinder assembly (skid control ECU) CAN branch wire or connector
  • Power source circuit of brake booster with master cylinder assembly (skid control ECU)
  • Brake booster with master cylinder assembly (skid control ECU) ground circuit
  • Brake booster with master cylinder assembly (skid control ECU)

WIRING DIAGRAM

CAUTION / NOTICE / HINT

CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.

NOTICE:

  • Inspect the fuses for circuits related to this system before performing the following inspection procedure.
  • Before measuring the resistance of the CAN bus, turn the power switch off and leave the vehicle for 1 minute or more without operating the key, switches or opening or closing the doors. After that, disconnect the cable from the negative (-) auxiliary battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.
  • After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal.

    Click here

  • When disconnecting and reconnecting the auxiliary battery.

    Click here

    HINT:

    When disconnecting and reconnecting the auxiliary battery, there is an automatic learning function that completes learning when the respective system is used.

    Click here

  • Some parts must be initialized and set when replacing or removing and installing parts.

    Click here

  • Because the order of diagnosis is important to allow correct diagnosis, make sure to begin troubleshooting using How to Proceed with Troubleshooting when CAN communication system related DTCs are output.

    Click here

  • After performing repairs, perform the DTC check procedure and confirm that the DTCs are not output again.

    DTC check procedure: Turn the power switch on (IG) and wait for 1 minute or more. Then operate the suspected malfunctioning system and drive the vehicle at 60 km/h (37 mph) or more for 5 minutes or more.

  • After the repair, perform CAN Bus Check and check that all the ECUs and sensors connected to the CAN communication system are displayed as normal.

    Click here

HINT:

  • Operating the power switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.
  • Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below may help determine the cause of the malfunction.

PROCEDURE

1.

CHECK FOR OPEN IN CAN BUS WIRE (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY [SKID CONTROL ECU] BRANCH WIRE)

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

(b) Disconnect the brake booster with master cylinder assembly (skid control ECU) connector.

*a

Front view of wire harness connector

(to Brake Booster with Master Cylinder Assembly [Skid Control ECU])

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A57-37 (CA1H) - A57-38 (CA1L)

Cable disconnected from negative (-) auxiliary battery terminal

54 to 69 Ω

NG

REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR

OK

2.

CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A57-28 (GND) - Body ground

Cable disconnected from negative (-) auxiliary battery terminal

Below 1 Ω

A57-27 (GND2) - Body ground

Cable disconnected from negative (-) auxiliary battery terminal

Below 1 Ω

A57-26 (GND3) - Body ground

Cable disconnected from negative (-) auxiliary battery terminal

Below 1 Ω

A57-25 (GND4) - Body ground

Cable disconnected from negative (-) auxiliary battery terminal

Below 1 Ω

A57-24 (GND5) - Body ground

Cable disconnected from negative (-) auxiliary battery terminal

Below 1 Ω

A57-23 (GND6) - Body ground

Cable disconnected from negative (-) auxiliary battery terminal

Below 1 Ω

*a

Front view of wire harness connector

(to Brake Booster with Master Cylinder Assembly [Skid Control ECU])

(b) Reconnect the cable to the negative (-) auxiliary battery terminal.

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

A57-15 (BS) - Body ground

Power switch off

11 to 14 V

A57-14 (BI) - Body ground

Power switch off

11 to 14 V

A57-16 (IG1) - Body ground

Power switch on (IG)

11 to 14 V

Power switch off

Below 1 V

A57-12 (IG2) - Body ground

Power switch on (IG)

11 to 14 V

Power switch off

Below 1 V

OK

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY (SKID CONTROL ECU)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

READ NEXT:

 Clearance Warning ECU Communication Stop Mode

DESCRIPTION Detection Item Symptom Trouble Area Clearance Warning ECU Communication Stop Mode Any of the following conditions are met: Communication stop for "Clearance Warning (Intuit

 Air Conditioning Amplifier Communication Stop Mode

DESCRIPTION Detection Item Symptom Trouble Area Air Conditioning Amplifier Communication Stop Mode Any of the following conditions are met: Communication stop for "Air Conditioning Amp

 Power Steering ECU Communication Stop Mode

DESCRIPTION Detection Item Symptoms Trouble Area Power Steering ECU Communication Stop Mode Any of the following conditions are met: Communication stop for "Power Steering (EPS)" is in

SEE MORE:

 Installation

INSTALLATION CAUTION / NOTICE / HINT NOTICE: Handle components indoors as much as possible to prevent foreign matter from entering and adhering to headlight assembly components. Do not reuse parts which have reduced fastening ability due to thread damage. When installing components, make sure

 ECO Switch Circuit

DESCRIPTION When the integration control and panel assembly (ECO mode switch) is turned on, the air conditioning amplifier assembly receives an integration control and panel assembly (ECO mode switch) ON signal and controls the air conditioning to enhance fuel efficiency. WIRING DIAGRAM CAUTION / N

© 2016-2024 Copyright www.lexunx.com