ANTI-LOCK BRAKE SYSTEM PROBLEM SYMPTOMS TABLE

If there are no DTCs output and the problem still occurs, check the suspected areas for each problem symptom in the order given in the following table and proceed to the relevant troubleshooting page.

Note:

When replacing the skid control ECU (brake actuator assembly), sensors, etc., turn the ignition switch off.

Tip:

Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each symptom by checking the suspected areas in the order they are listed. Replace parts as necessary.
Inspect the fuses and relays related to this system before inspecting the suspected areas below.

Table 1. Anti-lock Brake System
Symptom	Suspected Area	Link
ABS and/or EBD does not operate	Check again to see if DTCs are output. (if DTCs are output, perform diagnosis based on the DTCs that are output.)	Click here
	Power source circuit (low power supply voltage malfunction)	Click here
	Power source circuit (high power supply voltage malfunction)	Click here
	Front speed sensor circuit	Click here
	Rear speed sensor circuit	Click here
	Check the brake actuator assembly using the GTS. (Check brake actuator assembly operation using the Active Test function.) If abnormal, check the hydraulic circuit for leaks.	Click here
	If the symptoms still occur even after the above suspected areas have been inspected and proved to be normal, replace the skid control ECU (Brake actuator assembly).	Click here
ABS and/or EBD does not operate efficiently	Check again to see if DTCs are output. (if DTCs are output, perform diagnosis based on the DTCs that are output.)	Click here
	Front speed sensor circuit	Click here
	Rear speed sensor circuit	Click here
	Stop light switch circuit	Click here
	Check the brake actuator assembly using the GTS. (Check brake actuator assembly operation using the Active Test function.) If abnormal, check the hydraulic circuit for leaks.	Click here
	If the symptoms still occur even after the above suspected areas have been inspected and proved to be normal, replace the skid control ECU (Brake actuator assembly).	Click here
ABS sensor DTC check cannot be done	Check again to see if DTCs are output. (if DTCs are output, perform diagnosis based on the DTCs that are output.)	Click here
	TC and CG terminal circuit	Click here
	If the symptoms still occur even after the above suspected areas have been inspected and proved to be normal, replace the skid control ECU (Brake actuator assembly).	Click here
ABS warning light abnormal (Remains on)	ABS warning light circuit	Click here
ABS warning light abnormal (Remains on)	Skid control ECU (Brake actuator assembly)	Click here
ABS warning light abnormal (Does not come on)	ABS warning light circuit	Click here
ABS warning light abnormal (Does not come on)	Skid control ECU (Brake actuator assembly)	Click here
Brake warning light abnormal (Remains on)	Brake warning light circuit	Click here
Brake warning light abnormal (Remains on)	Skid control ECU (Brake actuator assembly)	Click here
Brake warning light abnormal (Does not come on)	Brake warning light circuit	Click here
Brake warning light abnormal (Does not come on)	Skid control ECU (Brake actuator assembly)	Click here
Sensor check cannot be done	TS and CG terminal circuit	Click here
Sensor check cannot be done	Skid control ECU (Brake actuator assembly)	Click here