Lexus ES: Control Module Communication Bus OFF (U0073,U0100,U0124,U0129,U0293)
DESCRIPTION
The parking brake ECU (brake actuator assembly) communicates with the hybrid vehicle control ECU assembly, skid control ECU (brake booster with master cylinder assembly) and deceleration sensor (airbag ECU assembly) via CAN communication.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Memory | Note |
| U0073 | Control Module Communication Bus OFF | Both of following conditions are met: -
Power switch on (IG)
-
Bus is off (communication with other ECUs is not possible).
| CAN communication system | DTC stored | An electric parking brake system malfunction is displayed on the multi-information display. |
| U0100 | Lost Communication With ECM/PCM "A" | Both of following conditions are met: -
Vehicle being driven at 6 km/h (4 mph) or more.
-
Parking brake ECU (brake actuator assembly) cannot receive signals from the ECM for approximately 15 seconds.
| -
CAN communication system
-
ECM
| DTC stored | An electric parking brake system malfunction is displayed on the multi-information display. |
| U0124 | Lost Communication With Lateral Acceleration Sensor Module | Both of following conditions are met: -
Vehicle is being driven at 6 km/h (4 mph) or more.
-
Parking brake ECU (brake actuator assembly) cannot receive signals from the deceleration sensor (airbag ECU assembly) for approximately 15 seconds.
| -
CAN communication system
-
Deceleration sensor (Airbag ECU assembly)
| DTC stored | An electric parking brake system malfunction is displayed on the multi-information display. |
| U0129 | Lost Communication with Brake System Control Module | Both of following conditions are met: -
Power switch on (IG).
-
Parking brake ECU (brake actuator assembly) cannot receive signals from the skid control ECU (brake booster with master cylinder assembly) for approximately 15 seconds or 30 seconds (malfunction duration differs depending on the signal).
| -
CAN communication system
-
Skid control ECU (brake booster with master cylinder assembly)
| DTC stored | An electric parking brake system malfunction is displayed on the multi-information display. |
| U0293 | Lost Communication With Hybrid Vehicle Control System | Both of following conditions are met: -
Vehicle being driven at 6 km/h (4 mph) or more.
-
Parking brake ECU cannot receive signals from the hybrid vehicle control ECU for approximately 15 seconds.
| -
CAN communication system
-
Hybrid vehicle control ECU
| DTC stored | An electric parking brake system malfunction is displayed on the multi-information display. |
PROCEDURE
| 1. | GO TO CAN COMMUNICATION SYSTEM |
(a) Go to CAN communication system.
Click here
| NEXT | | END |
READ NEXT:
OPERATION METHOD PROCEDURE 1. PRECAUTION Click here 2. SEPARATE REAR SEAT CUSHION ASSEMBLY Click here 3. REMOVE REAR SEAT CUSHION LOCK HOOK Click here 4. SEPARATE REAR SEATBACK ASSEMBLY (
SEE MORE:
ON-VEHICLE INSPECTION PROCEDURE 1. INSPECT PARKING BRAKE ACTUATOR ASSEMBLY (for Gasoline Model) HINT: Using the GTS to perform the Utilities allows relays, VSVs and actuators and other items to be operated without removing any parts. This non-intrusive functional inspection can be very useful becaus
TERMINALS OF ECU BLIND SPOT MONITOR SENSOR RH Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition R4-4 (OMIR) - R4-10 (BRGD) SB - W-B Outer rear view mirror indicator RH power source Outer rear view mirror indicator RH illuminated 3.5 to 9.5
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