Antilock Brakes / Traction Control Systems: Service Precautions

BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: PRECAUTION; 2013 MY FR-S [03/2012 -]

1. TROUBLESHOOTING PRECAUTIONS

(a) When there is a malfunction with terminal contact points or part installation problems, removal and installation of the suspected parts may return the system to normal either completely or temporarily.

(b) In order to determine the malfunctioning area, be sure to check the conditions at the time the malfunction occurred, such as DTC output and the Freeze Frame Data, and record it before disconnecting any connector or removing and installing parts.

(c) Since the system may be influenced by malfunctions in systems other than the VSC system, be sure to check for DTCs in other systems.

2. HANDLING PRECAUTIONS

(a) Do not remove or install VSC parts such as the steering sensor except when required, as they need to be adjusted correctly after removal and installation.

(b) Be sure to perform preparation before work and confirmation after work is completed by following the directions in the repair manual when working on the VSC system.

(c) Be sure to remove and install the ECU, brake actuator assembly, sensors, etc. with the ignition switch off unless it is otherwise specified in the inspection procedure.

(d) If the ECU, brake actuator assembly or a sensor has been removed and installed, it is necessary to check the system for problems after the parts have been reassembled. Check for DTCs using the Techstream, also check that system functions and signals received by the ECU are normal using Test Mode.

3. DTC PRECAUTION

(a) Warnings for some DTCs cannot be cleared only by repairing the malfunctioning parts. If the warning is displayed after repair work, the DTC should be cleared after turning the ignition switch off.

NOTICE:
If a DTC for a malfunctioning part reappears after it was cleared, then it has been stored again.

4. CHASSIS DYNAMOMETER PRECAUTION

When testing with a 2-wheel drum tester such as a speedometer tester, a combination tester for the speedometer and brakes, a chassis dynamometer, or when jacking up the front wheels and turning the wheels, perform the following procedure to enter Inspection Mode and stop the TR(A)C and VSC systems.

Enter Inspection Mode to disable TR(A)C and VSC operation when using a chassis dynamometer.

HINT
* If Inspection Mode is not used, the vehicle may unexpectedly move off the dynamometer because of TR(A)C and VSC operation.
* The VSC OFF switch must not be used to disable TR(A)C and VSC operation when the vehicle is to be operated on a dynamometer. Pressing the VSC OFF switch does not disable TR(A)C and VSC operation completely.

NOTICE:
Secure the vehicle with lock chains for safety.

(a) Activating Inspection Mode (When Using the Techstream)

(1) Ensure that the ignition switch is off and the engine is stopped.

(2) Make sure that the shift lever is in P.

(3) Connect the Techstream to the DLC3.

(4) Start the engine.

(5) Turn the Techstream on.

(6) Enter the following menus: Chassis / ABS/VSC/TRAC / Utility / Inspection Mode.

(7) Check that the VSC OFF indicator light will come on.

HINT
* If the VSC OFF indicator light does not come on, repeat the steps.
* Turning the ignition switch off ends Inspection Mode.

(b) Activating Inspection Mode (When not Using the Techstream)

HINT
Perform steps "C" to "H" within 30 seconds.

(1) Ensure that the ignition switch is off and the engine is stopped (Step "A").

(2) for Manual Transmission:

Check that the shift lever is in neutral (Step "B").

for Automatic Transmission:

Make sure that the shift lever is in P (Step "B").

(3) Start the engine (Step "C").

(4) Apply the parking brake by pulling up the parking brake lever (Step "D").

(5) Depress and release the brake pedal twice (Step "E").

(6) While holding the brake pedal down, release and apply the parking brake twice (Step "F").

(7) With the parking brake applied, depress and release the brake pedal twice (Step "G").

(8) Check if the slip indicator light will come on (Step "H").

HINT
* If the slip indicator light does not come on in step "H", repeat steps "A" to "H".
* Turning the ignition switch off ends Inspection Mode.

5. CAN COMMUNICATION SYSTEM PRECAUTIONS

(a) The CAN communication system is used for communication between the skid control ECU (brake actuator assembly), the steering sensor and other ECUs. If any CAN communication DTCs are detected, DTCs corresponding to the malfunction will be output.

(b) If any CAN communication DTCs are output, repair the malfunction and troubleshoot the VSC system while communication is normal.

(c) In order to enable CAN communication, a specific type of wiring is used for the CAN communication lines. The wiring used for each communication line is a twisted pair of wires that have an equal length. A bypass wire should not be used because the data being transmitted will be corrupted.