Toyota Avalon (XX50): Dtc Check / Clear. Excessive Brake Pedal Travel (No Fluid Leaks and No Air in System). Fail-safe Chart

Dtc Check / Clear

DTC CHECK / CLEAR

HINT:

• DTCs which are stored in the skid control ECU (brake booster with master cylinder assembly) can be displayed on the Techstream. The Techstream can display the current, pending and permanent DTCs.
• If a malfunction is detected during the current driving cycle, current and permanent DTCs are stored.
• Current DTCs can be cleared by using the Techstream. However, permanent DTCs cannot be cleared using either of these two methods.
• After clearing current DTCs using the Techstream, permanent DTCs can be cleared when the system is determined to be normal for the relevant DTCs and then the universal trip is performed. The driving pattern to obtain a normal judgment is described under the "Confirmation Driving Pattern" for the respective DTC.

HINT:

• Obtaining a normal judgment and performing a universal trip driving pattern can be done in the same driving cycle or in different driving cycles.
• Ensure to wait at least 2 minutes between each trip.

CHECK DTC

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Chassis / ABS/VSC/TRAC / Trouble Codes.

(e) Check the DTC(s) and freeze frame data, and then write them down.

(f) Check the details of the DTC(s).

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CLEAR DTC (PENDING AND CURRENT DTC)

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Chassis / ABS/VSC/TRAC / Trouble Codes.

(e) Clear the DTCs.

CLEAR PERMANENT DTC

HINT:

Even if the following procedure is not performed, permanent DTCs are cleared by obtaining a normal judgment during 3 consecutive driving cycles.

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Chassis / ABS/VSC/TRAC / Trouble Codes.

HINT:

If "PERMANENT" in the top right of the screen displays "YES", permanent DTCs are stored.

(e) Change the tab from "Enhanced" to "Generic".

(f) Check if permanent DTCs are stored.

HINT:

If permanent DTCs are not output, it is not necessary to continue this procedure.

(g) Clear the DTCs.

(h) Perform the respective confirmation driving patterns in order to obtain a normal judgment for the output DTCs.

HINT:

For the confirmation driving pattern, refer to the procedures for the relevant DTC.

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(i) Perform the universal trip.

CAUTION:

When performing a driving pattern, obey all speed limits and traffic laws.

1. Put the engine in Inspection Mode (Maintenance Mode).

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2. Start the engine.
3. Idle the engine for 30 seconds or more.
4. With the engine running, drive the vehicle at 40 km/h (25 mph) or more for a total of 5 minutes or more.

   HINT:

   • It is possible to complete the drive pattern even if the vehicle decelerates to less than 40 km/h (25 mph) during the driving cycle provided that the vehicle is driven at 40 km/h (25 mph) or more for a total of 5 minutes.
   • If the engine stops, further depress the accelerator pedal to restart the engine.
5. Allow 10 minutes or more to elapse from the time the engine is started.

(j) Turn the power switch off.

(k) Wait 2 minutes or more.

(l) Turn the power switch on (IG).

(m) Enter the following menus: Chassis / ABS/VSC/TRAC / Trouble Codes.

(n) Check that the permanent DTCs have been cleared.

HINT:

The permanent DTCs are cleared when the universal trip is completed.

Excessive Brake Pedal Travel (No Fluid Leaks and No Air in System)

DESCRIPTION

Depending on the malfunction, the skid control ECU (brake booster with master cylinder assembly) prohibits operation of the electronically controlled brake system to protect components and prevent incorrect operation when DTCs are stored.

If the switching solenoid is disabled due to prohibition of the electronically controlled brake system, the response of the brake pedal changes and braking performance is reduced.

CAUTION / NOTICE / HINT

NOTICE:

After replacing the skid control ECU (brake booster with master cylinder assembly), perform linear solenoid valve offset learning, ABS holding solenoid valve learning, yaw rate and acceleration sensor zero point calibration and system information memorization after performing "Reset Memory".

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PROCEDURE

(a) Check the conditions at the time the problem occurred.

(1) Whether a warning light illuminated or the buzzer sounded.

(2) Road surface condition when the problem occurred and just before the problem occurred.

(3) When the problem occurred and how many times the brake pedal was depressed before the problem occurred.

(4) Frequency of the abnormal brake pedal response.

NEXT

(a) Using the Techstream, check DTCs and Freeze Frame Data.

Click here

HINT:

• If there are currently no warnings and the brake pedal travel is not excessive, DTCs may have been cleared after the system returned to normal.
• If the brake pedal response returned to normal and there are currently no warnings, the system is normal.

B

REPAIR CIRCUITS INDICATED BY OUTPUT DTCS

A

(a) While depressing the brake pedal by hand, check the installation condition of the brake pedal stroke sensor assembly and brake pedal, and check for mechanical malfunctions.

(b) Check and adjust the brake pedal height.

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NEXT

(a) Check the brake booster with master cylinder assembly.

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OK:

The brake booster with master cylinder assembly is normal.

OK

USE SIMULATION METHOD TO CHECK

NG

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

Fail-safe Chart

FAIL-SAFE CHART

FAIL-SAFE FUNCTION OF CONTROL SYSTEM

(a) When a malfunction is detected in the brake control system, the skid control ECU (brake booster with master cylinder assembly) turns the ABS warning, brake warning / red (malfunction), brake warning / yellow (minor malfunction) and slip indicator lights on, flashes the brake hold operated indicator light*, as well as prohibits ABS, BA, TRAC, VSC, secondary collision brake and brake hold operation.

• *: The brake hold switch (electric parking brake switch assembly) is turned on under the following vehicle conditions.
  • Vehicle Conditions:
    1. The driver side door is closed.
    2. The driver side seat belt is fastened.

(b) If the skid control ECU (brake booster with master cylinder assembly) detects that a system related to the hybrid control system is malfunctioning, it will prohibit operation of the TRAC and VSC systems in order to prevent further malfunctions and to protect the systems.

(c) Brake hold control prohibits brake hold operation in order to protect the system and prevent improper operation when the electronically controlled brake system, electric parking brake system or hybrid control system is malfunctioning.

(d) If the skid control ECU (brake booster with master cylinder assembly) detects that a system related to the airbag system is malfunctioning, it will prohibit operation of the secondary collision brake in order to prevent further malfunctions and to protect the systems.

• *: Only during brake hold control

FAIL-SAFE FUNCTION OF HYDRAULIC SYSTEM

(a) If a malfunction is detected in the skid control ECU (brake booster with master cylinder assembly), brake actuator (brake booster with master cylinder assembly) or an individual sensor, control will be stopped and brake effort will be generated by the hydraulic brake booster (brake booster with master cylinder assembly).

(b) If brake control is stopped due to a malfunction in the hydraulic pressure source, the pressure generated in the master cylinder by the driver is applied to the wheel cylinders to ensure braking force.