Intuitive Parking Assist System (Diagnostic Codes & Circuit Tests): Overview Lexus CT I

DESCRIPTION

The No. 1 ultrasonic sensor (front left sensor) is installed on the front bumper. The ECU detects obstacles based on signals received from the No. 1 ultrasonic sensor (front left sensor). If the No. 1 ultrasonic sensor (front left sensor) has an open circuit or other malfunction, it will not function normally.

The No. 1 ultrasonic sensor (front right sensor) is installed on the front bumper. The ECU detects obstacles based on signals received from the No. 1 ultrasonic sensor (front right sensor). If the No. 1 ultrasonic sensor (front right sensor) has an open circuit or other malfunction, it will not function normally.

The No. 1 ultrasonic sensor (rear left sensor) is installed on the rear bumper. The ECU detects obstacles based on signals received from the No. 1 ultrasonic sensor (rear left sensor). If the No. 1 ultrasonic sensor (rear left sensor) has an open circuit or other malfunction, it will not function normally.

The No. 1 ultrasonic sensor (rear left center sensor) is installed on the rear bumper. The ECU detects obstacles based on signals received from the No. 1 ultrasonic sensor (rear left center sensor). If the No. 1 ultrasonic sensor (rear left center sensor) has an open circuit or other malfunction, it will not function normally.

The No. 1 ultrasonic sensor (rear right center sensor) is installed on the rear bumper. The ECU detects obstacles based on signals received from the No. 1 ultrasonic sensor (rear right center sensor). If the No. 1 ultrasonic sensor (rear right center sensor) has an open circuit or other malfunction, it will not function normally.

The No. 1 ultrasonic sensor (rear right sensor) is installed on the rear bumper. The ECU detects obstacles based on signals received from the No. 1 ultrasonic sensor (rear right sensor). If the No. 1 ultrasonic sensor (rear right sensor) has an open circuit or other malfunction, it will not function normally.

This DTC is stored when there is an open or short circuit in the communication line between the front sensors and the ECU, or when there is a malfunction in a front sensor.

Scheme 67

Scheme 68

1. CHECK DTC OUTPUT (C1AEC) Check for DTCs. Refer to «DTC CHECK / CLEAR»(ref-568594-S12386610772013072300000) . Clear the DTCs. Refer to «DTC CHECK / CLEAR»(ref-568594-S12386610772013072300000) . Recheck for DTCs. Refer to «DTC CHECK / CLEAR»(ref-568594-S12386610772013072300000) . Result Result Proceed to DTC C1AEC is output A No DTC is output B B --> See step 11 A: Go to next step
2. CHECK HARNESS AND CONNECTOR (CLEARANCE WARNING ECU ASSEMBLY - FRONT LEFT SENSOR) Disconnect the A49 connector from the clearance warning ECU assembly. Disconnect the C3 connector from the No. 1 ultrasonic sensor. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition A49-9 (BOF) - C3-1 (BI) Always Below 1 ohms A49-8 (SOF) - C3-3 (SI) A49-24 (E5) - C3-5 (EI) A49-9 (BOF) - Body ground 10 kohms or higher A49-8 (SOF) - Body ground A49-24 (E5) - Body ground NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (FRONT LEFT SENSOR - FRONT RIGHT SENSOR) Disconnect the C3 and C4 connectors from the No. 1 ultrasonic sensors. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition C3-2 (BO) - C4-1 (BI) Always Below 1 ohms C3-4 (SO) - C4-3 (SI) C3-6 (EO) - C4-5 (EI) C3-2 (BO) - Body ground 10 kohms or higher C3-4 (SO) - Body ground C3-6 (EO) - Body ground NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK NO. 1 ULTRASONIC SENSOR (FRONT LEFT SENSOR) Remove the No. 1 ultrasonic sensor (front left sensor). Refer to «REMOVAL»(ref-568781-S33562809112013072300000) . Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 1 (BI) - 5 (EI) Always 10 kohms or higher 1 (BI) - 2 (BO) 3 (SI) - 4 (SO) Below 1 ohms 5 (EI) - 6 (EO) TEXT IN ILLUSTRATION *a Component without harness connected (No. 1 Ultrasonic Sensor (Front Left Sensor)) NG --> See step 10 OK: Go to next step
5. REPLACE NO. 1 ULTRASONIC SENSOR (FRONT LEFT SENSOR) See step 2 NEXT: Go to next step
6. CHECK DTC OUTPUT (C1AEC) Clear the DTCs. Refer to «DTC CHECK / CLEAR»(ref-568594-S12386610772013072300000) . Check for DTCs. Refer to «DTC CHECK / CLEAR»(ref-568594-S12386610772013072300000) . Result Result Proceed to DTC C1AEC is output A No DTC is output B B --> END (FRONT LEFT SENSOR WAS DEFECTIVE) A: Go to next step
7. REPLACE NO. 1 ULTRASONIC SENSOR (FRONT RIGHT SENSOR) See step 2 NEXT: Go to next step
8. CHECK DTC OUTPUT (C1AEC) Clear the DTCs. Refer to «DTC CHECK / CLEAR»(ref-568594-S12386610772013072300000) . Check for DTCs. Refer to «DTC CHECK / CLEAR»(ref-568594-S12386610772013072300000) . Result Result Proceed to DTC C1AEC is output A No DTC is output B B --> END (FRONT RIGHT SENSOR WAS DEFECTIVE) A --> See step 9
9. REPLACE CLEARANCE WARNING ECU ASSEMBLY. Refer to «REMOVAL»(ref-568781-S17975771172013072300000)
10. REPLACE NO. 1 ULTRASONIC SENSOR (FRONT LEFT SENSOR). Refer to «REMOVAL»(ref-568781-S33562809112013072300000)
11. USE SIMULATION METHOD TO CHECK. Refer to «HOW TO PROCEED WITH TROUBLESHOOTING»(ref-568589-S05901111982013072300000)

This DTC is stored when there is an open or short circuit in the communication line between the rear sensors and the ECU, or when there is a malfunction in a rear sensor.

Scheme 69

These DTCs are stored when the clearance warning ECU assembly cannot receive and recognize several signals via the CAN communication system.

HINT

When 2 or more DTCs starting with "U" are output simultaneously, inspect the connectors and wire harnesses of each ECU.

The back sonar or clearance sonar switch assembly is installed at the base of the driver side instrument panel.

When the back sonar or clearance sonar switch assembly is turned on, an ON signal is sent to the clearance warning ECU assembly. The intuitive parking assist system operates according to this signal.

Scheme 70

This circuit consists of a power source, the No. 1 clearance warning buzzer and clearance warning ECU assembly. An ECU-excited type buzzer is used. The auxiliary battery voltage supplied through the buzzer is grounded inside the clearance warning ECU assembly using a pulsed digital pattern, producing sound. The ECU operates the buzzer using a sound pattern that changes depending on the distance to the obstacle.

Scheme 71

This circuit provides power to operate the clearance warning ECU assembly.

Scheme 72