Lexus ES: Control Module Communication Bus Off (U0073,U0100,U0126,U0129)
DESCRIPTION
The 4WD ECU assembly inputs the signals sent from the ECM, skid control ECU (brake actuator assembly) and steering sensor via CAN communication.
When DTCs indicating a CAN communication system malfunction are output, repair the CAN communication system before repairing each corresponding sensor.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area |
|---|---|---|---|
| U0073 | Control Module Communication Bus Off |
|
|
| U0100 | Lost Communication with ECM / PCM "A" |
|
|
| U0126 | Lost Communication with Steering Angle Sensor Module |
|
|
| U0129 | Lost Communication with Brake System Control Module |
|
|
| Vehicle Condition | |||
|---|---|---|---|
| Pattern 1 | Pattern 2 | ||
| Diagnosis Condition | One or more times within 0.1 seconds. | - | ○ |
| Malfunction Status | Signals from the 4WD ECU assembly are not received. | ○ | - |
| A communication malfunction (bus off) occurs. | - | ○ | |
| Detection Time | 5 seconds or more | 10 times consecutively | |
| Number of Trips | 1 trip | 1 trip | |
| Vehicle Condition | |||
|---|---|---|---|
| Pattern 1 | Pattern 2 | ||
| Diagnosis Condition | The voltage of the IG1 terminal is 10 V or more. | ○ | ○ |
| Malfunction Status | Communication with the steering sensor cannot be performed. | ○ | - |
| The condition that communication with the steering sensor cannot be performed occurs once within 5 seconds. | - | ○ | |
| Detection Time | 1 second or more | 10 times or more within 60 seconds | |
| Number of Trips | 1 trip | 1 trip | |
PROCEDURE
| 1. | CHECK FOR DTC |
(a) Check for DTCs.
Chassis > Four Wheel Drive > Trouble Codes(b) Record the output DTCs (dynamic torque control AWD system).
HINT:
When DTCs indicating a CAN communication system malfunction are output, repair the CAN communication system before repairing each corresponding sensor.
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