If the PID value is unstable, inspect for poor connection.
1. Any one or a combination of the ABS warning and BRAKE system warning lights illuminate even when the system is normal.
Warning lights that may illuminate and/or flash
Condition under which the light may illuminate
Conditions under which the light will go out
ABS, EBD control
Any or all the following lights illuminate:
ABS warning light
BRAKE system warning light (*1)
Under any of the following conditions:
When the front wheels are jacked up, stuck, or placed on a chassis roller, and only the front wheel ABS wheel speed sensors are spun for 20 s or more.
After turning ignition switch off, vehicle is driven at speed greater than 10 km/h {6.2 mph} and normal operation is confirmed.
ABS: Disables control.
EBD:
Disable control, in cases where the light may illuminate, only when ABS HU/CM detects that wheel speed sensors determine that two or more rear wheels are malfunctioning.
Enables control, if wheel speed sensors determine that three or more wheels are functioning correctly.
Parking brake is not fully released while driving.
Brake drag.
Sudden acceleration/deceleration.
Left/right or front/rear tires are different. (Size, radius, tire pressure, or wear is other than that listed on tire label.)
All the following lights illuminate:
ABS warning light
BRAKE system warning light
Battery voltage at ABS HU/CM ignition terminal J drops below approx. 9 to 10 V. (*2)
Battery voltage rises above approx. 10 V.
(Only BRAKE system warning light goes out.)
ABS: Enables control.
EBD: Enables control.
- *1
- The light will illuminate only when ABS HU/CM detects that a rear wheel‐speed sensor is malfunctioning.
- *2
- If battery voltage drops below 9 V while vehicle speed is greater than 6 km/h {3.7 mph} , the ABS HU/CM stores DTC B1318.
2. Precautions during servicing of ABSThe ABS is composed of electrical and mechanical parts. It is necessary to categorize malfunctions as being either electrical or hydraulic when performing troubleshooting.
a. Malfunctions in electrical system
The ABS HU/CM has an on-board diagnostic function. With this function, any one or a combination of the ABS warning light and BRAKE system warning light will illuminate when there is a problem in the electrical system. Also, past and present malfunctions are stored in the ABS HU/CM. This function can find malfunctions that do not occur during periodic inspections. Connect the M-MDS to the DLC‐2. Stored malfunctions will be displayed in the order of occurrence. To find out the causes of ABS malfunctions, use these on-board diagnostic results.
If a malfunction occurred in the past but is now normal, the cause is likely a temporary poor connection of the wiring harness. The ABS HU/CM usually operates normally. Be careful when searching for the cause of malfunction.
After repair, it is necessary to clear the DTC from the ABS HU/CM memory.
Also, if the ABS related parts have been replaced, verify that no DTC is displayed after repairs.
After repairing the ABS wheel-speed sensor or ABS sensor rotor, or after replacing the ABS HU/CM, the ABS warning light may not go out (*) even when the ignition switch is turned to the ON position. In this case, drive the vehicle at a speed of 10 km/h {6.2 mph} or more, make sure that ABS warning light goes out, and then clear the DTC.
* The BRAKE system warning light also illuminates when there is any rear wheel deformation.
When repairing, if the ABS related connectors are disconnected and the ignition switch is turned to the ON position, the ABS HU/CM will mistakenly detect a fault and record it as a malfunction.
To protect the ABS HU/CM, make sure the ignition is off before connecting or disconnecting the ABS HU/CM connector.
b. Malfunctions in hydraulic system
Symptoms in a hydraulic system malfunction are similar to those in a conventional brake malfunction. However, it is necessary to determine if the malfunction is in an ABS component or the conventional brake system.
The ABS hydraulic unit contains delicate mechanical parts. If foreign material gets into the component, the ABS may fail to operate. Also, it will likely become extremely difficult to find the location of the malfunction in the event that the brakes operate but the ABS does not. Make sure foreign material does not enter when servicing the ABS (e.g. brake fluid replacement, pipe removal).
1. The ABS warning light and/or BRAKE system warning light and/or DSC indicator light and/or DSC OFF light illuminate even when the system is normal.
Warning lights that may illuminate and/or flash
Condition under which the light may illuminate
Conditions under which the light will go out
ABS, EBD, TCS and DSC control
ABS warning light
BRAKE system warning light
DSC indicator light
Under any of the following conditions:
When the front wheels are jacked up, stuck, or placed on a chassis roller, and only the front wheel ABS wheel speed sensors are spun for 20 s or more.
After turning ignition switch off, vehicle is driven at speed greater than 10 km/h {6.2 mph} and normal operation is confirmed.
ABS: Disables control.
EBD:
Disable control, in cases where the light may illuminate, only when ABS HU/CM detects that wheel speed sensors determine that two or more wheels are malfunctioning.
Enables control, if wheel speed sensors determine three or more wheels are functioning correctly.
TCS: Disables control.
DSC: Disables control.
Parking brake is not fully released while driving.
Brake drag.
Sudden
acceleration/deceleration.
Left/right or front/rear tires are different. (Size, radius, tire pressure, or wear is other than that listed on tire label.)
Battery voltage at DSC HU/CM ignition terminal drops below approx. 10 V.
Battery voltage rises above approx. 10 V.
ABS: Disables control.
EBD: Enables control.
TCS: Disables control.
DSC: Disables control.
Brake system warning light
Brake fluid amount is low.
Brake fluid level lower than recommended amount.
ABS: Enables control.
EBD: Enables control.
TCS: Enables control.
DSC: Enables control.
2. Precautions during servicing of DSCThe DSC is composed of electrical and mechanical parts. It is necessary to categorize malfunctions as being either electrical or hydraulic when performing troubleshooting.
a. Malfunction in electrical system
The control module has an on-board diagnostic function. With this function, the ABS warning light and/or BRAKE system warning light and/or DSC indicator light and/or DSC OFF light will illuminate when there is a problem in the electrical system.
Also, past and present malfunctions are in the control module. This function can find malfunctions that do not occur during periodic inspections. Connect the M-MDS to the DLC-2, the stored malfunctions will be displayed in the order of occurrence. To find out the causes of DSC malfunctions, use these on-board diagnostic results.
If a malfunction occurred in the past but is now normal, the cause is likely a temporary poor connection of the wiring harness.
The control module usually operates normally. Be careful when searching for the cause of malfunction.
After repair, it is necessary to clear the DTC from the control module memory.
Also, if the DSC related parts have been replaced, verify that no DTC is displayed after repairs.
After repairing the ABS wheel-speed sensor or ABS sensor rotor, or after replacing the control module, the ABS warning light may not go out even when the ignition switch is turned to the ON position. In this case, drive the vehicle at a speed of more than 10 km/h {6.2 mph}, make sure the ABS warning light goes out, and then clear the DTC.
When repairing, if the DSC related connectors are disconnected and the ignition switch is turned to the ON position, the control module will mistakenly detect a fault and record it as a malfunction.
CAUTION:
In DSC vehicles, when the DSC HU/CM, steering angle sensor, or combined sensor is replaced, perform the initialization procedure for each sensor. (See STEERING ANGLE SENSOR INITIALIZATION PROCEDURE.) (See COMBINED SENSOR INITIALIZATION PROCEDURE.) (See STEERING ANGLE SIGNAL INITIALIZATION PROCEDURE.)
To protect the control module, make sure the ignition is off before connecting or disconnecting the control module connector.
b. Malfunctions in hydraulic system
Symptoms in a hydraulic system malfunction are similar to those in a conventional brake malfunction. However, it is necessary to determine if the malfunction is in a DSC component or the conventional brake system.
The hydraulic unit contains delicate mechanical parts. If foreign material gets into the component, the DSC may fail to operate. Also, it will likely become extremely difficult to find the location of the malfunction in the event that the brakes operate but the DSC does not. Make sure foreign material does not enter when servicing the DSC (e.g.brake fluid replacement, pipe removal).
If a malfunction occurs or becomes worse while driving on a rough road or when the engine is vibrating, perform the following steps.
NOTE:
There are several reasons why vehicle or engine vibration could cause an electrical malfunction. Inspect the following:
Connectors not fully seated.
Wire harnesses not having full play.
Wires laying across brackets or moving parts.
Wires routed too close to hot parts.
An improperly routed, improperly clamped, or loose harness can cause wiring to become pinched between parts.
The connector joints, points of vibration, and places where wiring harnesses pass through the firewall, body and other panels are the major areas to be inspected.
1. Connect the M-MDS to DLC-2.
2. Turn the ignition switch to the ON position (engine off).NOTE:
If the engine starts and runs, perform the following steps at idle.
3. Access PIDs for the switch you are inspecting.
4. Turn the switch on manually.
5. Slightly shake each connector or wiring harness vertically and horizontally while monitoring the PID.
If the PID value is unstable, inspect for poor connection.
1. Connect the M-MDS to the DLC-2.
2. Turn the ignition switch to the ON position (engine off).NOTE:
If the engine starts and runs, perform the following steps at idle.
3. Access PIDs for the switch you are inspecting.
4. Slightly shake each connector or wiring harness vertically and horizontally while monitoring the PID.
If the PID value is unstable, inspect for poor connection.
1. Connect the M-MDS to DLC-2.
2. Turn the ignition switch to the ON position (engine off).NOTE:
If engine starts and runs, perform the following steps at idle.
3. Access PIDs for the switch you are inspecting.
4. Vibrate the sensor slightly with your finger.
If the PID value is unstable or a malfunction occurs, inspect for poor connection and/or poorly mounted sensor.
1. Perform the malfunction reappearance test according to malfunction reappearance mode and malfunction data monitor. The malfunction cause is found in the malfunction data.
1. Inspect the connection condition of each female terminal.
2. Insert the male terminal, and fit the female terminal side to female terminal. Inspect if the malfunction is in the female terminal.
