Anti-lock braking system (ABS) [Toyota Camry Vista-V40]

Description of the diagnostic system

The electronic control unit has a fail-safe system that detects a system malfunction. When a malfunction is detected, the electronic control unit switches off the ABS system and the ABS indicator lights up on the instrument cluster. 4WD models use a deceleration sensor that sends a signal to the ABS electronic control unit when braking.

Checking the ABS system

1. Make sure the battery voltage is (with ignition off) corresponds to the nominal value.

• Nominal voltage - 10-14 V

2. Check the ABS indicator.

a) Turn on the ignition.

b) Make sure the indicator lights up for three seconds. If not, repair or replace (if necessary) fuse, indicator lamp and wiring harness.

3. Read the fault code.

a) Turn on the ignition.

b) Short-circuit the terminals "T_WITH" and "E₁" of the diagnostic connector.



c) Make sure that the jumper on the "WA" and "WB" terminals of the diagnostic connector is removed.

Note: On some models, the ABS system will only be diagnosed with the jumper installed.

d) If there is a malfunction, the indicator will start flashing after 4 seconds. Count the number of flashes.

Note:

• The fault code consists of two digits, the first digit is determined by the initial series of flashes, then after a pause of 1.5 seconds, a second series of flashes follows, which corresponds to the second digit of the code.
• If there are two or more fault codes, the smallest code will be displayed first, followed by the others in ascending order. There will be a 2.5 second pause between codes.

d) If there is no fault, the indicator will flash at 0.5 second intervals.





e) After troubleshooting, erase the codes stored in the electronic control unit.

Note: If the battery is disconnected, all fault codes stored in the electronic control unit will be erased.

g) Disconnect the terminals "T_C" and "E₁" of the diagnostic connector.



c) Install a jumper on the "WA" and "WB" terminals.



i) Turn on the ignition and make sure that the ABS indicator comes on for three seconds and goes out.

Resetting fault codes

1. Method for resetting fault codes No.1.

a) Turn on the ignition.

b) Short-circuit the terminals "T_WITH" and "E₁" of the diagnostic connector.

Note: This operation must be performed with the vehicle stationary.

c) Press the brake pedal eight or more times within 3 seconds to clear the fault codes stored in the ABS control unit memory.

d) Make sure that the indicator flashes correspond to the normal state code (interval 0.5 seconds).

d) Turn off the ignition.

e) Disconnect the terminals "T_WITH" and "E₁" of the diagnostic connector.

g) Make sure the ABS indicator goes out.

2. Method for resetting fault codes No.2.

a) Turn off the ignition.

6) Remove the "ECU-B" fuse (5A) for 10 seconds or more depending on the ambient temperature (the lower the temperature, the longer).



c) Make sure the fault codes are cleared (ABS indicator went out).

Diagnostics of rotation speed and deceleration sensors

Note: When diagnosing speed sensors, the brake system operates as normal (ABS does not work).

1. Make sure the battery voltage is (with ignition off) corresponds to the nominal value.

• Nominal voltage - 10-14 V

2. Check the ABS indicator.

a) Turn on the ignition.

b) Make sure the indicator lights up for three seconds. If not, repair or replace (if necessary) fuse, indicator lamp and wiring harness.

3. Read the fault codes.

a) Turn off the ignition.

b) Short-circuit the terminals "T_S" and "E₁" of the diagnostic connector and make sure that the jumper on the "WA" and "WB" terminals of the diagnostic connector is removed.

Note: On some models, the ABS system will only be diagnosed when the jumper is installed.

c) Turn on the ignition.

d) If the ABS system is normal, the indicator blinks as shown in the figure.

ABS system normal state code



(): models since 1996.







4. (Speed sensors (ABS)) Checking when the car is moving.

a) Tighten the parking brake lever.

b) Accelerate the vehicle to a speed of over 80 km/h for a few seconds. Make sure that the indicator flashes according to the diagram in the figure.



Table. ABS system fault codes





^*1: only for 4WD before 1996.
^*2: models before 1996.
^*3: models since 1996.

5. Reading fault codes.

a) Stop the car. The ABS indicator will flash

b) Short-circuit the terminals "T_WITH" and "E₁" of the diagnostic connector.

Note: remove the jumper between terminals "T_S" and "E₁" of the diagnostic connector.

c) Determine the fault code by the number of flashes of the ABS indicator (see the table "Fault codes for the speed sensors and deceleration sensor").

Note:

• During normal operation, the indicator flashes 2 times per second.
• If there are two or more faults, the fault with the lowest code will be displayed first.

6. (Slowdown sensor)

Check the response height of the deceleration sensor.

a) Raise the rear of the vehicle.

Attention: Please measure the height as shown in the picture.

b) Check that the indicator light is flashing. If the indicator light is constantly on, check the voltage between the "IG" terminal of the deceleration sensor connector and the "ground".

• Nominal voltage - 10-14 V

If the voltage is normal, replace the deceleration sensor.

c) Lower the vehicle.

d) Raise the front of the car. Then repeat steps "b" and "c".

Attention: Please measure the height as shown in the picture.

7. (Slowdown sensor) Check while driving.

a) Check that the ABS indicator is blinking. If the indicator is constantly on, check the voltage between the "IG" terminal of the sensor connector and the "ground".

• Nominal voltage - 10 - 14 V

If the voltage is normal, replace the deceleration sensor.

b) At speeds over 20 km/h, lightly press the brake pedal.

c) Make sure the indicator light flashes as shown in the figure.



d) At speeds over 20 km/h, press the brake pedal harder.

d) Make sure that when you press the brake pedal, the indicator flashes as shown in the figure.



Table. Error codes for speed sensors and deceleration sensor



e) At a speed of more than 20 km/h, press the brake pedal all the way down

g) Make sure that the indicator light flashes when you press the brake pedal as shown in the figure.



If the indicator blinks do not match the description, check that the deceleration sensor is installed correctly. If the deceleration sensor was installed correctly, replace it.

8. Replace or repair faulty system components.

Note: When repairing or replacing ABS parts, turn off the ignition.

9. Disconnect the terminals of the "T_WITH", "E_S" and "E₁" of the diagnostic connector.

Troubleshooting

1. If the ABS indicator lights up continuously after turning on the ignition and while driving.

a) Disconnect the jumper from the diagnostic connector and short-circuit the terminals "T_WITH" and "E₁". Check for fault codes (ignition on).

b) Check that the connector is connected correctly to the ABS control unit and that all terminals are present in the connector.

c) With the ignition on, check for 10 - 14 V between the "STP" terminal of the control unit connector and "ground". If there is no voltage, the power supply circuit is faulty.

d) With the ignition off, disconnect the control unit connector and the diagnostic connector. Turn on the ignition. If the indicator continues to light, there is a short circuit in the wiring harness between the "WA" terminal of the ABS control unit and the "WA" terminal of the control relay. If the indicator goes out, the control unit is faulty.

2. The ABS indicator does not light for 3 seconds after the ignition is turned on.

a) With the ignition off, remove the jumper and ground the "WA" terminal on the socket part of the connector. Turn on the ignition. If the indicator does not light, the indicator lamp is faulty or there is a break in the circuit between the indicator and the "WA" terminal of the control relay.

b) With the ignition off, disconnect the connectors from the control unit and control relay, and ground the "WA" terminal or the control unit connector on the wire side. Turn on the ignition. If the indicator does not light, there is an open circuit between the indicator and the "WA" terminal of the control unit.

c) With the ignition off, disconnect the control relay connectors and check for continuity between the "WA" and "GND" terminals on the modulator side. Reverse the polarity of the connection and check again. If the continuity is one-way, the control unit is faulty. If the continuity is not one-way, there is a short circuit in the diode inside the control relay.

Note: If the diode is short-circuited, the "WA" terminal is inoperative. When checking the terminal, connect the control unit connector, and disconnect the diagnostic connector and the pressure modulator connector. Then turn on the ignition. If the indicator does not light, the control unit connector terminal is faulty.

3. If the ABS indicator lights up and goes out, check for a short circuit between the terminals "T_WITH" or "E_S" and "E₁" of the diagnostic connector

4. If the car pulls to the side when braking; insufficient brake performance; ABS is activated during normal braking; ABS intervenes before stopping during normal braking; strong pulsation of the brake pedal when ABS is operating:

a) Remove the jumper and short-circuit the terminals "T_WITH" and "E₁" of the diagnostic connector.

b) With the ignition on, check for any fault codes.

c) Check that the speed and deceleration sensors are installed correctly and that the tightening torques of the mounting bolts comply with the permissible standards.

d) Check the diagnostic system of the speed sensors and the deceleration sensor. If the signal level is different from normal, check the speed sensors and replace them if necessary.

d) Check the diagnostic system of the speed sensors and the deceleration sensor. If the signal change is normal, then check the sensor rotors and replace them if necessary.

e) Disconnect the connector from the ABS control unit and check the continuity between the speed sensor terminals on the wire side. The speed sensor wiring harness is faulty if there is a change in conductivity when you try to twist or bend it.

g) Check for foreign material or metal shavings on the end of the sensor.

h) Check the operation of the speed and deceleration sensors through the diagnostic system. If the sensor does not work correctly, then either the sensor is faulty or it is installed incorrectly.

i) Check the operation of the pressure modulator. If the modulator works normally, replace the control unit.

5. If you hear the sound of rubber slipping while the ABS is operating (ABS is not working effectively enough).

a) Remove the jumper and short-circuit the terminals "T_WITH" and "E₁" of the diagnostic connector.

b) With the ignition on, check for any fault codes.

c) Check the voltage between the "STP" terminal of the control unit and "ground" with the brake pedal depressed. If the voltage does not match the battery voltage, there is an open circuit between the brake light switch and/or a break in the wiring harness.

d) Check the pressure modulator.