ELECTRONICALLY CONTROLLED BRAKE SYSTEM > PROBLEM SYMPTOMS TABLE

for Preparation Click here

If there are no DTCs but the problem still occurs, check the circuits for each problem symptom in the order given in the table below and proceed to the relevant troubleshooting page.

NOTICE:

When replacing the brake booster with master cylinder (skid control ECU), sensor, etc., make sure that the power switch is turned off, the stop light switch is off, and 2 minutes have elapsed since the driver's door was closed.

HINT:

Since the hydraulic passage is blocked off by the master cut solenoid during electronically controlled brake system control, there is no kickback (vibration) to the brake pedal, creating a quiet sound even while the ABS is operating.
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.

Electronically Controlled Brake System
Symptom	Suspected Area	See page
ABS, BA and/or EBD does not operate	Use a chassis dynamometer, etc. to check the electronically controlled brake system operation.	-
	Check the DTC again and make sure that the normal system code is output.	Click here
	IG power source circuit	Click here
	Front speed sensor circuit	Click here
	Rear speed sensor circuit	Click here
	Check the brake booster with master cylinder (brake actuator) using the intelligent tester. (Check brake booster with master cylinder (brake actuator) 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 circuits in suspected areas have been inspected and proved to be normal, replace the brake booster with master cylinder (skid control ECU) (for LHD).	Click here
	If the symptoms still occur even after the above circuits in suspected areas have been inspected and proved to be normal, replace the brake booster with master cylinder (skid control ECU) (for RHD).	Click here
ABS, BA and/or EBD does not operate efficiently	Check the DTC again and make sure that the normal system code is output.	Click here
	Front speed sensor circuit	Click here
	Rear speed sensor circuit	Click here
	Check the brake booster with master cylinder (brake actuator) using the intelligent tester. (Check brake booster with master cylinder (brake actuator) 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 circuits in suspected areas have been inspected and proved to be normal, replace the brake booster with master cylinder (skid control ECU) (for LHD).	Click here
	If the symptoms still occur even after the above circuits in suspected areas have been inspected and proved to be normal, replace the brake booster with master cylinder (skid control ECU) (for RHD).	Click here
ABS warning light abnormal (Remains on)	ABS warning light circuit	Click here
	Brake booster with master cylinder (Skid control ECU) (for LHD)	Click here
	Brake booster with master cylinder (Skid control ECU) (for RHD)	Click here
ABS warning light abnormal (Does not come on)	ABS warning light circuit	Click here
	Brake booster with master cylinder (Skid control ECU) (for LHD)	Click here
	Brake booster with master cylinder (Skid control ECU) (for RHD)	Click here
Brake warning light / red (malfunction) abnormal (Remains on)	Brake fluid level warning switch circuit	Click here
	Brake warning light / red (malfunction) circuit	Click here
	Brake booster with master cylinder (Skid control ECU) (for LHD)	Click here
	Brake booster with master cylinder (Skid control ECU) (for RHD)	Click here
Brake warning light / red (malfunction) abnormal (Does not come on)	Brake warning light / red (malfunction) circuit	Click here
	Brake booster with master cylinder (Skid control ECU) (for LHD)	Click here
	Brake booster with master cylinder (Skid control ECU) (for RHD)	Click here
VSC and/or TRC does not operate	Check that traction control has not operated by carrying out diagnosis.	-
	Check the DTC again and make sure that the normal system code is output.	Click here
	IG power source circuit	Click here
	Check the hydraulic circuit for leaks.	-
	Front speed sensor circuit	Click here
	Rear speed sensor circuit	Click here
	Yaw rate and acceleration sensor circuit	Click here
	Steering angle sensor circuit	Click here
	If the symptoms still occur even after the above circuits in suspected areas have been inspected and proved to be normal, replace the brake booster with master cylinder (skid control ECU) (for LHD).	Click here
	If the symptoms still occur even after the above circuits in suspected areas have been inspected and proved to be normal, replace the brake booster with master cylinder (skid control ECU) (for RHD).	Click here
Brake warning light / yellow (minor malfunction) abnormal (Remains on)	Brake warning light / yellow (minor malfunction) circuit	Click here
	Brake booster with master cylinder (Skid control ECU) (for LHD)	Click here
	Brake booster with master cylinder (Skid control ECU) (for RHD)	Click here
Brake warning light / yellow (minor malfunction) abnormal (Does not come on)	Brake warning light / yellow (minor malfunction) circuit	Click here
	Brake booster with master cylinder (Skid control ECU) (for LHD)	Click here
	Brake booster with master cylinder (Skid control ECU) (for RHD)	Click here
Slip indicator light abnormal (Remains on)	Slip indicator light circuit	Click here
	Brake booster with master cylinder (Skid control ECU) (for LHD)	Click here
	Brake booster with master cylinder (Skid control ECU) (for RHD)	Click here
Slip indicator light abnormal (Does not come on)	Slip indicator light circuit	Click here
	Brake booster with master cylinder (Skid control ECU) (for LHD)	Click here
	Brake booster with master cylinder (Skid control ECU) (for RHD)	Click here
DTC check cannot be done	Check the DTC again and make sure that the normal system code is output.	Click here
	TC and CG terminal circuit	Click here
	If the symptoms still occur even after the above circuit in suspected areas has been inspected and proved to be normal, replace the brake booster with master cylinder (skid control ECU) (for LHD).	Click here
	If the symptoms still occur even after the above circuit in suspected areas has been inspected and proved to be normal, replace the brake booster with master cylinder (skid control ECU) (for RHD).	Click here
Sensor check cannot be done	TS and CG terminal circuit	Click here
	Brake booster with master cylinder (Skid control ECU) (for LHD)	Click here
	Brake booster with master cylinder (Skid control ECU) (for RHD)	Click here
Meter buzzer abnormal	Meter buzzer circuit	Click here
	Brake booster with master cylinder (Skid control ECU) (for LHD)	Click here
	Brake booster with master cylinder (Skid control ECU) (for RHD)	Click here
Skid control buzzer abnormal*1	Skid control buzzer circuit	Click here
	Brake booster with master cylinder (Skid control ECU) (for LHD)	Click here
	Brake booster with master cylinder (Skid control ECU) (for RHD)	Click here

*1: w/ Dynamic Radar Cruise Control System