Lexus ES manuals

Lexus ES: ECM Communication Stop Mode

Lexus ES (XZ10) Service Manual / Power Source & Network / Networking / Can Communication System (for Hv Model) / ECM Communication Stop Mode

DESCRIPTION

Detection Item

Symptom

Trouble Area

ECM Communication Stop Mode

Any of the following conditions are met:

  • Communication stop for "ECM (Engine)" is indicated on the "Communication Bus Check" screen of the Techstream.

    Click here

  • Communication stop history for "ECM (Engine)" is indicated on the "Communication Bus Check (Detail)" screen of the Techstream. (The Lost Communication Time value for "ECM (Engine)" is 6 or more.)

    Click here

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

    Click here

  • ECM main line or connector
  • ECM branch line or connector
  • Power source circuit of ECM
  • ECM ground circuit
  • ECM

WIRING DIAGRAM

CAUTION / NOTICE / HINT

CAUTION:

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

NOTICE:

  • 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

  • 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 or any 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. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work.

    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 the CAN bus check and check that all the ECUs and sensors connected to the CAN communication system are displayed as normal.

    Click here

  • Inspect the fuses for circuits related to this system before performing the following procedure.

HINT:

  • Before disconnecting related connectors for inspection, push in on each connector body to check that the connector is not loose or disconnected.
  • When a connector is disconnected, check that the terminals and connector body are not cracked, deformed or corroded.

PROCEDURE

1.

CHECK FOR OPEN IN CAN BUS LINES (ECM MAIN LINE AND BRANCH LINE)

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

(b) Disconnect the A26 ECM connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A26-7 (CAN+) - A26-17 (CAN-)

Cable disconnected from negative (-) auxiliary battery terminal

54 to 69 Ω

A26-8 (CANH) - A26-18 (CANL)

Cable disconnected from negative (-) auxiliary battery terminal

108 to 132 Ω

*a

Front view of wire harness connector

(to ECM)
Result

 Proceed to

OK

A

NG (No. 2 junction connector main line)

B

NG (No. 2 CAN junction connector branch line)

C
B

REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (ECM)
C

REPAIR OR REPLACE CAN BRANCH LINES OR CONNECTOR (ECM)
A

2.

CHECK ECM POWER SOURCE CIRCUIT

(a) Check the ECM power source circuit.

Click here

OK

REPLACE ECM

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

READ NEXT:

 Steering Angle Sensor Communication Stop Mode

DESCRIPTION Detection Item Symptom Trouble Area Steering Angle Sensor Communication Stop Mode Any of the following conditions are met: Communication stop for "Spiral cable (Steering An

 Power Steering ECU Communication Stop Mode

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

 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

SEE MORE:

 Data List / Active Test

DATA LIST / ACTIVE TEST DATA LIST NOTICE: In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a part is faulty or not. HINT: Using the Techstream to read the Data List allows the values or states of

 Parts Location

PARTS LOCATION ILLUSTRATION *1 TIRE PRESSURE WARNING ECU AND RECEIVER *2 TIRE PRESSURE WARNING VALVE AND TRANSMITTER ILLUSTRATION *1 STEERING PAD SWITCH ASSEMBLY *2 COMBINATION METER ASSEMBLY - TIRE PRESSURE WARNING LIGHT - MULTI-INFORMATION DISPLAY *3 MAIN BODY ECU (MUL

© 2016-2025 Copyright www.lexguide.net