DTC C1A74: Steering Vibrator System Malfunction [11/2017 - 01/2023]: Procedure

1. Disconnect the z10 spiral cable sub-assembly connector.
2. Turn the engine switch on (IG).
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   z10-4 (BHT) (spiral cable sub-assembly side) - Body ground	Engine switch on (IG)	11 to 14 V

4. Turn the engine switch off.
5. Connect the z10 spiral cable sub-assembly connector.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  6

Result: 

OK 

See step  2

1. Disconnect the z10 spiral cable sub-assembly connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   z10-1 (EHT) (spiral cable sub-assembly side) - Body ground	Always	Below 1 Ω

3. Connect the z10 spiral cable sub-assembly connector.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  5

Result: 

OK 

See step  3

1. Replace the steering vibration ECU (steering vibration and heater ECU).

   Refer to REMOVAL [11/2017 - ]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  4

1. Clear the DTCs.

   Refer to DTC CHECK / CLEAR [11/2017 - 01/2023]

   Chassis > LKA/LDA > Clear DTCs 

2. Perform the following procedure.

   HINT: 

   If the following procedure is not performed, the previously output DTC cannot be detected.

   1. Turn the engine switch on (IG).
   2. Turn the lane departure alert system (w/ Steering Control) ON.
   3. Drive the vehicle at a speed of 5 km/h (4 mph) or more for 5 seconds or more.
3. Check for DTCs.

   Refer to DTC CHECK / CLEAR [11/2017 - 01/2023]

   Chassis > LKA/LDA > Trouble Codes 

   Result

   Result	Proceed to
   DTC C1A74 is not output	A
   DTC C1A74 is output	B

Result: 

A 

END (STEERING VIBRATION ECU (STEERING VIBRATION AND HEATER ECU) WAS DEFECTIVE) 

Result: 

B 

REPLACE FORWARD RECOGNITION CAMERA. Refer to  COMPONENTS [11/2017 - 01/2023] 

1. Disconnect the O144 spiral cable sub-assembly connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   O144-2 (EHT) (connector side) - Body ground	Always	Below 1 Ω

3. Connect the O144 spiral cable sub-assembly connector.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE SPIRAL CABLE SUB-ASSEMBLY. Refer to  COMPONENTS [11/2017 - 03/2019]  , or refer to  COMPONENTS [03/2019 - 01/2023] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (SPIRAL CABLE SUB-ASSEMBLY - BODY GROUND) 

1. Disconnect the O144 spiral cable sub-assembly connector.
2. Turn the engine switch on (IG).
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   O144-4 (BHT) (connector side) - Body ground	Engine switch on (IG)	11 to 14 V

4. Turn the engine switch off.
5. Connect the O144 spiral cable sub-assembly connector.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE SPIRAL CABLE SUB-ASSEMBLY. Refer to  COMPONENTS [11/2017 - 03/2019]  , or refer to  COMPONENTS [03/2019 - 01/2023] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (STEERING VIBRATION ECU (STEERING VIBRATION AND HEATER ECU) POWER SOURCE CIRCUIT)