Lexus NX: Stop Light Relay Circuit (C1A4B)
DESCRIPTION
When a stop light relay circuit malfunction signal sent from the pre-collision system is detected by the clearance warning ECU assembly, DTC C1A4B is stored.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area |
|---|---|---|---|
| C1A4B | Stop Light Relay Circuit | Stop light relay circuit malfunction | Pre-collision system |
CAUTION / NOTICE / HINT
NOTICE:
-
After the power switch is turned off, there may be a waiting time before disconnecting the negative (-) auxiliary battery terminal.
Click here
.gif)
-
When disconnecting and reconnecting the auxiliary battery
Click here
HINT:
When disconnecting and reconnecting the auxiliary battery, there is an automatic learning function that completes learning when the respective system is used.
Click here
-
After replacing an ultrasonic sensor or the clearance warning ECU assembly, perform the necessary procedures (adjustment, calibration, initialization or registration).
Click here
-
When DTC C1A4B is stored, there may be a malfunction in the lighting system. Inspect the lighting system before performing the following procedure.
Click here
PROCEDURE
| 1. | CHECK FOR DTC |
(a) Using the Techstream, check for DTCs according to the prompts on the screen.
Click here
HINT:
After turning the power switch from off to on (IG), wait 4 seconds or more before checking for DTCs.
Body Electrical > Advanced Parking Guidance/ICS/Intuitive P/A > Trouble Codes(b) Clear the DTCs according to the screen on the Techstream.
Click here
(c) Recheck for DTCs.
Click here
HINT:
- DTC C1A4B is stored when a malfunction signal sent from the pre-collision system is detected.
- If the malfunctioning part has been repaired or replaced before rechecking for DTCs, DTC C1A4B will not be output again.
-
If DTC C1A4B is output frequently, duplicate the conditions that cause the problem symptoms and perform the inspection again, even though the DTC was not output when rechecking for DTCs.
Click here
| Result | Proceed to |
|---|---|
| DTC C1A4B is output | A |
| DTC C1A4B is not output | B |
| A | .gif) | GO TO PRE-COLLISION SYSTEM |
| B | | USE SIMULATION METHOD TO CHECK |
READ NEXT:
Brake System (C1A50)
DESCRIPTION When an electronically controlled brake system malfunction signal sent from the brake booster with master cylinder assembly (skid control ECU) is detected by the clearance warning ECU asse
Steering Angle Midpoint Initial Setting Incomplete (C1AEA)
DESCRIPTION When the clearance warning ECU assembly detects that the steering angle neutral point memorization is incomplete during self-diagnosis, C1AEA is stored. DTC No. Detection Item DTC D
ICS Detection Area Adjustment Incomplete (C1AF0)
DESCRIPTION When ICS detection area adjustment is incomplete, the clearance warning ECU assembly stores DTC C1AF0. DTC No. Detection Item DTC Detection Condition Trouble Area C1AF0 ICS
SEE MORE:
How To Proceed With Troubleshooting
CAUTION / NOTICE / HINT PRECAUTIONS WHEN TROUBLESHOOTING NOTICE:
Because the order of diagnosis is important to allow correct diagnosis, make sure to begin troubleshooting using How to Proceed with Troubleshooting when CAN communication system related DTCs are output.
If the CAN communication s
How To Proceed With Troubleshooting
CAUTION / NOTICE / HINT HINT:
Use the following procedure to troubleshoot the lighting system.
*: Use the Techstream.
PROCEDURE 1. VEHICLE BROUGHT TO WORKSHOP
NEXT 2. INSPECT AUXILIARY BATTERY VOLTAGE (a) Measure the auxiliary battery voltage with the power
