Lexus NX: Control Module Communication Bus OFF (U0073,U0124,U0129,U0293)
DESCRIPTION
The parking brake ECU assembly communicates with the hybrid vehicle control ECU, 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 | With the power switch on (IG), the bus is off (communication with other ECUs is not possible) | CAN communication system | Yes | An electric parking brake system malfunction is displayed on the multi-information display. |
| U0124 | Lost Communication With Lateral Acceleration Sensor Module | With the power switch on (IG) and the vehicle being driven at 7 km/h (4.3 mph) or more, the parking brake ECU assembly cannot receive signals from the deceleration sensor (airbag ECU assembly). |
| Yes | An electric parking brake system malfunction is displayed on the multi-information display. |
| U0129 | Lost Communication with Brake System Control Module | With the power switch on (IG), the parking brake ECU assembly cannot receive signals from the skid control ECU (brake booster with master cylinder assembly) for approximately 1 second or 10 seconds (malfunction duration differs depending on the signal). |
| Yes | An electric parking brake system malfunction is displayed on the multi-information display. |
| U0293 | Lost Communication with EV ECU | With the power switch on (IG), the parking brake ECU assembly cannot receive signals from the hybrid vehicle control ECU for approximately 1 second or 10 seconds (malfunction duration differs depending on the signal). |
| Yes | 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 .gif)
| NEXT | .gif) | END |
READ NEXT:
Electric Parking Brake does not Operate
WIRING DIAGRAM CAUTION / NOTICE / HINT NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
Before disconnecting connectors or fuse
Electric Parking Brake System AUTO Function Circuit
DESCRIPTION The parking brake ECU assembly receives shift position information from the hybrid vehicle control ECU via CAN communication. Also, the parking brake ECU assembly receives wheel speed info
Electric Parking Brake AUTO Indicator Light Circuit
WIRING DIAGRAM CAUTION / NOTICE / HINT NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
Before disconnecting connectors or fuse
SEE MORE:
Removal
REMOVAL CAUTION / NOTICE / HINT HINT:
Use the same procedure for the RH and LH sides.
The following procedure is for the LH side.
NOTICE:
When the brake pedal is first depressed after replacing the brake pads or pushing back the disc brake piston, DTC C1214 may be output. As there is no m
Inspection
INSPECTION PROCEDURE 1. INSPECT AIR FUEL RATIO SENSOR (a) Measure the resistance according to the value(s) in the table below. Standard Resistance: Tester Connection Condition Specified Condition 1 (HA1A) - 2 (+B) 20°C (68°F) 1.6 to 3.2 Ω If the result is not as specified, r
