DTC B1B40:14 [PARKING ASSIST UNIT]
id0902q6240800
| Description | Front corner ultrasonic sensor (LH) circuit malfunction | 
|---|---|
| Detection condition | •  The parking assist unit detected a front corner ultrasonic sensor (LH) circuit malfunction with the ignition switched ON (engine off or on). | 
| Fail-safe | Not applicable | 
| Possible cause | •  Front bumper external appearance damage or incorrect front bumper installation 
 •  Front corner ultrasonic sensor (LH) malfunction •  Front corner ultrasonic sensor (LH) connector or terminal malfunction •  Parking assist unit connector or terminal malfunction •  Short to ground in wiring harness between the following terminals: 
 •  Short to power supply in wiring harness between the following terminals: 
 •  Open circuit in wiring harness between the following terminals: 
 •  Parking assist unit malfunction | 
|  | |
Diagnostic Procedure
| Step | Inspection | Action | |
|---|---|---|---|
| 1 | VERIFY OTHER PARKING ASSIST UNIT DTCs •  Clear the DTC for the parking assist unit using the M-MDS.
 •  Retrieve the parking assist unit DTCs using the M-MDS.
 •  Is DTC U3000:49 displayed? | Yes | Replace the parking assist unit, then go to Step 9. | 
| No | Go to the next step. | ||
| 2 | VERIFY FRONT BUMPER EXTERNAL APPEARANCE AND INSTALLATION CONDITION •  Verify that the front bumper external appearance and installation condition. •  Are the front bumper external appearance and installation condition normal? | Yes | Go to the next step. | 
| No | Repair or replace the front bumper, then go to Step 9. | ||
| 3 | PERFORM DTC INSPECTION AND VERIFY FRONT CORNER ULTRASONIC SENSOR (LH) MALFUNCTION 
 •  Switch the ignition off. •  Disconnect the negative battery cable.
 •  Disconnect the front corner ultrasonic sensor (LH) connector and the front corner ultrasonic sensor (RH) connector. •  Switch the front corner ultrasonic sensor (LH) with the front corner ultrasonic sensor (RH).
 •  Always reconnect all disconnected connectors. •  Connect the negative battery cable.
 •  Clear the DTC for the parking assist unit using the M-MDS.
 •  Switch the ignition ON (engine off or on) and wait for 5 s or more. •  Retrieve the parking assist unit DTCs using the M-MDS.
 •  Is DTC B1B40:14 or B1B36:14 displayed? | Yes | If DTC B1B40:14 is displayed: •  Go to the next step. If DTC B1B36:14 is displayed: •  Replace the front corner ultrasonic sensor (RH) (front corner ultrasonic sensor (LH) before switching), then go to Step 9.
 | 
| No | Return the switched sensor to its original position, and perform the DTC inspection for the parking assist unit. If DTC B1B40:14 is displayed: •  Go to the next step. If DTC B1B40:14 is not displayed: •  Go to Step 10. | ||
| 4 | INSPECT FRONT CORNER ULTRASONIC SENSOR (LH) CONNECTOR CONDITION •  Switch the ignition off. •  Disconnect the negative battery cable.
 •  Disconnect the front corner ultrasonic sensor (LH) connector. •  Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection. •  Is the connector normal? | Yes | Go to the next step. | 
| No | Repair or replace the connector, then go to Step 9. | ||
| 5 | INSPECT PARKING ASSIST UNIT CONNECTOR CONDITION •  Disconnect the parking assist unit connector. •  Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection. •  Is the connector normal? | Yes | Go to the next step. | 
| No | Repair or replace the connector, then go to Step 9. | ||
| 6 | INSPECT FRONT CORNER ULTRASONIC SENSOR (LH) CIRCUIT FOR SHORT TO GROUND •  Verify that the front corner ultrasonic sensor (LH) and parking assist unit connectors are disconnected. •  Inspect for continuity between the following terminals (wiring harness-side) and body ground: 
 •  Is there continuity? | Yes | Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals: •  Front corner ultrasonic sensor (LH) terminal A—Parking assist unit terminal J •  Front corner ultrasonic sensor (LH) terminal B—Parking assist unit terminal I If there is a common connector: •  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground. •  Repair or replace the malfunctioning part. If there is no common connector: •  Repair or replace the wiring harness which has a short to ground. Go to Step 9. | 
| No | Go to the next step. | ||
| 7 | INSPECT FRONT CORNER ULTRASONIC SENSOR (LH) CIRCUIT FOR SHORT TO POWER SUPPLY •  Verify that the front corner ultrasonic sensor (LH) and parking assist unit connectors are disconnected. •  Connect the negative battery cable.
 •  Switch the ignition ON (engine off or on). •  Measure the voltage at the following terminals (wiring harness-side): 
 •  Is the voltage 0 V? | Yes | Go to the next step. | 
| No | Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals: •  Front corner ultrasonic sensor (LH) terminal A—Parking assist unit terminal J •  Front corner ultrasonic sensor (LH) terminal B—Parking assist unit terminal I If there is a common connector: •  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power supply. •  Repair or replace the malfunctioning part. If there is no common connector: •  Repair or replace the wiring harness which has a short to power supply. Go to Step 9. | ||
| 8 | INSPECT FRONT CORNER ULTRASONIC SENSOR (LH) CIRCUIT FOR OPEN CIRCUIT •  Switch the ignition off. •  Disconnect the negative battery cable.
 •  Verify that the front corner ultrasonic sensor (LH) and parking assist unit connectors are disconnected. •  Inspect for continuity between the following terminals (wiring harness-side): 
 •  Is there continuity? | Yes | Go to the next step. | 
| No | Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals: •  Front corner ultrasonic sensor (LH) terminal A—Parking assist unit terminal J •  Front corner ultrasonic sensor (LH) terminal B—Parking assist unit terminal I If there is a common connector: •  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit. •  Repair or replace the malfunctioning part. If there is no common connector: •  Repair or replace the wiring harness which has an open circuit. Go to the next step. | ||
| 9 | VERIFY THAT REPAIRS HAVE BEEN COMPLETED •  Always reconnect all disconnected connectors. •  Connect the negative battery cable.
 •  Clear the DTC for the parking assist unit using the M-MDS.
 •  Retrieve the parking assist unit DTCs using the M-MDS.
 •  Is the same DTC displayed? | Yes | Repeat the inspection from Step 1. •  If the malfunction recurs, replace the parking assist unit.
 Go to the next step. | 
| No | Go to the next step. | ||
| 10 | VERIFY IF OTHER DTCs DISPLAYED •  Are any other DTCs displayed? | Yes | Repair or replace the malfunctioning part according to the applicable DTC troubleshooting. | 
| No | DTC troubleshooting completed. | ||