Park Assist Monitoring. Dtc C1Aec Front Sensor Communication Malfunction

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

DTC Code	DTC Detection Condition	Trouble Area
C1AEC	An open or short circuit in the communication line between the front sensors and ECU or a malfunction in a front sensor during initialization mode after the engine switch is turned on (IG).	Front ultrasonic sensor circuit Clearance warning ECU

WIRING DIAGRAM

Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Park Assist Monitoring.Toyota Parking Assist-Sensor System (W/ Multi-Display).
Dtc
C1Aec Front Sensor Communication Malfunction

INSPECTION PROCEDURE

1.CHECK FOR DTC

Clear the DTCs (LandCruiser RM000000VKU06EX.html).

Check for DTCs (LandCruiser RM000000VKU06EX.html).
Result
Result
Proceed to
No DTC is output
A
DTC C1AEC is output
B

Result
Result	Proceed to
No DTC is output	A
DTC C1AEC is output	B

Go to step 2

USE SIMULATION METHOD TO CHECK (LandCruiser RM000003YMJ00XX.html)

2.CHECK HARNESS AND CONNECTOR (CLEARANCE WARNING ECU - FRONT CORNER SENSOR LH)

Disconnect the G154 clearance warning ECU connector.

Disconnect the B7 No. 1 ultrasonic sensor (front corner sensor LH) connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
G154-21 (BOF) - B7-1 (BI)	Always	Below 1 Ω
G154-9 (SOF) - B7-3 (SI)	Always	Below 1 Ω
G154-19 (E1) - B7-5 (EI)	Always	Below 1 Ω
G154-21 (BOF) - Body ground	Always	10 kΩ or higher
G154-9 (SOF) - Body ground	Always	10 kΩ or higher
G154-19 (E1) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

3.CHECK HARNESS AND CONNECTOR (FRONT CORNER SENSOR LH - FRONT CENTER SENSOR LH)

Disconnect the B7 No. 1 ultrasonic sensor (front corner sensor LH) connector.

Disconnect the B8 No. 1 ultrasonic sensor (front center sensor LH) connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
B7-2 (BO) - B8-1 (BI)	Always	Below 1 Ω
B7-4 (SO) - B8-3 (SI)	Always	Below 1 Ω
B7-6 (EO) - B8-5 (EI)	Always	Below 1 Ω
B7-2 (BO) - Body ground	Always	10 kΩ or higher
B7-4 (SO) - Body ground	Always	10 kΩ or higher
B7-6 (EO) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

4.CHECK HARNESS AND CONNECTOR (FRONT CENTER SENSOR LH - FRONT CENTER SENSOR RH)

Disconnect the B8 No. 1 ultrasonic sensor (front center sensor LH) connector.

Disconnect the B9 No. 1 ultrasonic sensor (front center sensor RH) connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
B8-2 (BO) - B9-1 (BI)	Always	Below 1 Ω
B8-4 (SO) - B9-3 (SI)	Always	Below 1 Ω
B8-6 (EO) - B9-5 (EI)	Always	Below 1 Ω
B8-2 (BO) - Body ground	Always	10 kΩ or higher
B8-4 (SO) - Body ground	Always	10 kΩ or higher
B8-6 (EO) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

5.CHECK HARNESS AND CONNECTOR (FRONT CENTER SENSOR RH - FRONT CORNER SENSOR RH)

Disconnect the B9 No. 1 ultrasonic sensor (front center sensor RH) connector.

Disconnect the B10 No. 1 ultrasonic sensor (front corner sensor RH) connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
B9-2 (BO) - B10-1 (BI)	Always	Below 1 Ω
B9-4 (SO) - B10-3 (SI)	Always	Below 1 Ω
B9-6 (EO) - B10-5 (EI)	Always	Below 1 Ω
B9-2 (BO) - Body ground	Always	10 kΩ or higher
B9-4 (SO) - Body ground	Always	10 kΩ or higher
B9-6 (EO) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

6.INSPECT NO. 1 ULTRASONIC SENSOR (FRONT CORNER SENSOR LH)

Remove the No. 1 ultrasonic sensor (front corner sensor LH) (LandCruiser RM00000470F01EX.html).

Inspect the No. 1 ultrasonic sensor (front corner sensor LH) (LandCruiser RM00000472K01EX.html).

REPLACE NO. 1 ULTRASONIC SENSOR (FRONT CORNER SENSOR LH) (LandCruiser RM00000470F01EX.html)

OK

7.INSPECT NO. 1 ULTRASONIC SENSOR (FRONT CENTER SENSOR LH)

Remove the No. 1 ultrasonic sensor (front center sensor LH) (LandCruiser RM00000470F01EX.html).

Inspect the No. 1 ultrasonic sensor (front center sensor LH) (LandCruiser RM00000472K01EX.html).

REPLACE NO. 1 ULTRASONIC SENSOR (FRONT CENTER SENSOR LH) (LandCruiser RM00000470F01EX.html)

OK

8.INSPECT NO. 1 ULTRASONIC SENSOR (FRONT CENTER SENSOR RH)

Remove the No. 1 ultrasonic sensor (front center sensor RH) (LandCruiser RM00000470F01EX.html).

Inspect the No. 1 ultrasonic sensor (front center sensor RH) (LandCruiser RM00000472K01EX.html).

REPLACE NO. 1 ULTRASONIC SENSOR (FRONT CENTER SENSOR RH) (LandCruiser RM00000470F01EX.html)

OK

9.REPLACE NO. 1 ULTRASONIC SENSOR (FRONT CORNER SENSOR RH)

Replace the No. 1 ultrasonic sensor (front corner sensor RH) with a normally functioning sensor (LandCruiser RM00000470F01EX.html).

NEXT

10.CHECK FOR DTC (C1AEC)

Clear the DTCs (LandCruiser RM000000VKU06EX.html).

Check for DTCs (LandCruiser RM000000VKU06EX.html).
Result
Result
Proceed to
No DTC is output
A
DTC C1AEC is output
B

Go to step 11

END (NO. 1 ULTRASONIC SENSOR [FRONT CORNER SENSOR RH] WAS DEFECTIVE)

11.REPLACE NO. 1 ULTRASONIC SENSOR (FRONT CENTER SENSOR LH)

Replace the No. 1 ultrasonic sensor (front center sensor LH) with a normally functioning sensor (LandCruiser RM00000470F01EX.html).
HINT:
All of the sensors are interchangeable. To confirm whether a sensor is functioning normally, switch it with a known good sensor from the other end of the vehicle.

NEXT

12.CHECK FOR DTC (C1AEC)

Clear the DTCs (LandCruiser RM000000VKU06EX.html).

Check for DTCs (LandCruiser RM000000VKU06EX.html).
Result
Result
Proceed to
No DTC is output
A
DTC C1AEC is output
B

Go to step 13

END (NO. 1 ULTRASONIC SENSOR [FRONT CENTER SENSOR LH] WAS DEFECTIVE)

13.REPLACE NO. 1 ULTRASONIC SENSOR (FRONT CENTER SENSOR RH)

Replace the No. 1 ultrasonic sensor (front center sensor RH) with a normally functioning sensor (LandCruiser RM00000470F01EX.html).
HINT:
All of the sensors are interchangeable. To confirm whether a sensor is functioning normally, switch it with a known good sensor from the other end of the vehicle.

NEXT

14.CHECK FOR DTC (C1AEC)

Clear the DTCs (LandCruiser RM000000VKU06EX.html).

Check for DTCs (LandCruiser RM000000VKU06EX.html).
Result
Result
Proceed to
No DTC is output
A
DTC C1AEC is output
B

Go to step 15

END (NO. 1 ULTRASONIC SENSOR [FRONT CENTER SENSOR RH] WAS DEFECTIVE)

15.REPLACE NO. 1 ULTRASONIC SENSOR (FRONT CORNER SENSOR LH)

Replace the No. 1 ultrasonic sensor (front corner sensor LH) with a normally functioning sensor (LandCruiser RM00000470F01EX.html).
HINT:
All of the sensors are interchangeable. To confirm whether a sensor is functioning normally, switch it with a known good sensor from the other end of the vehicle.

NEXT

16.CHECK FOR DTC (C1AEC)

Clear the DTCs (LandCruiser RM000000VKU06EX.html).

Check for DTCs (LandCruiser RM000000VKU06EX.html).
Result
Result
Proceed to
No DTC is output
A
DTC C1AEC is output (for LHD)
B
DTC C1AEC is output (for RHD)
C

REPLACE CLEARANCE WARNING ECU (LandCruiser RM00000466X025X.html)

REPLACE CLEARANCE WARNING ECU (LandCruiser RM00000470500NX.html)

END (NO. 1 ULTRASONIC SENSOR [FRONT CORNER SENSOR RH] WAS DEFECTIVE)