Lexus ES: ABS does not Operate
DESCRIPTION
When the electronically controlled brake system is operating, as the input piston and output piston are not directly connected, the kickback of the brake pedal is minimal during ABS operation and the driver may not notice that ABS operated.
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
| 1. | BRAKE PROBLEM CHECK |
(a) Check if the slip indicator light was illuminated or blinking when ABS did not operate.
HINT:
- When the VSC system is normal and ABS is operating, the slip indicator light blinks.
- When the VSC system is malfunctioning, the slip indicator light illuminates.
| Result | Proceed to |
|---|---|
| The slip indicator light was blinking. | A |
| The slip indicator light was illuminated. | B |
| A | .gif) | END |
|
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| 2. | CHECK DTC AND FREEZE FRAME DATA |
(a) Using the Techstream, check DTCs and Freeze Frame Data.
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| Result | Proceed to |
|---|---|
| DTCs are not output. | A |
| DTCs are output. | B |
| B | | REPAIR CIRCUITS INDICATED BY OUTPUT DTCS |
|
| 3. | PERFORM OPERATION CHECK DRIVING |
(a) Check that ABS operates using a drum tester or equivalent.
CAUTION:
When using a drum tester, enter Inspection Mode or VSC off mode and perform inspection with the TRAC and VSC systems disabled to prevent the vehicle from moving suddenly due to TRAC or VSC operation.
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OK:
ABS operates.
| OK | | END |
| NG | | REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY |
