Lexus IS250 IS220d GSE20 ALE20 - BRAKE CONTROL
READ VALUE OF INTELLIGENT TESTER (MASTER CYLINDER PRESSURE SENSOR)
READ VALUE OF INTELLIGENT TESTER (STOP LIGHT SWITCH)
DTC C1246/46 Master Cylinder Pressure Sensor Malfunction
DTC C1281/81 Master Cylinder Pressure Sensor Output Malfunction (Test Mode DTC)
DESCRIPTION
Master cylinder pressure sensor is connected to the skid control ECU in the brake actuator assembly.
DTC C1281/81 can be deleted when the master cylinder pressure sensor sends a master cylinder pressure signal or the Test Mode ends. DTC C1281/81 is output only in the Test Mode.
| DTC No. | DTC Detection Condition | Trouble Area |
| C1246/46 | When any of the following is detected: At a vehicle speed of 4.3 mph (7 km/h) or more, when the PMC terminal voltage is over 0.86 V, it does not change by 0.005 V or more for 30 seconds. Noise occurs in the PMC terminal 7 times or more within 5 seconds. When the stop light switch is OFF, the PMC terminal voltage is more than 0.86 V or less than 0.3 V for 5 seconds or more. With the IG1 terminal voltage between 9.5 and 17.2 V, the VCM terminal voltage is not between 4.4 and 5.6 V for 1.2 seconds or more. When the VCM terminal voltage is between 4.4 and 5.6 V, the PCM terminal voltage is not between 0.14 and 4.85 V for 1.2 seconds or more. | Master cylinder pressure sensor Master cylinder pressure sensor circuit Stop light switch circuit Brake actuator assembly |
INSPECTION PROCEDURE
- NOTICE:
- When replacing the brake actuator assembly, perform zero point calibration .
| 1.CHECK STOP LIGHT OPERATION |
Check that the stop light comes on when the brake pedal is depressed, and goes off when the brake pedal is released.
- OK:
Condition Illumination Condition Brake pedal depressed ON Brake pedal released OFF
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| OK | |
| 2.READ VALUE OF INTELLIGENT TESTER (MASTER CYLINDER PRESSURE SENSOR) |
Connect the intelligent tester to the DLC3.
Start the engine.
Select the Data List mode on the intelligent tester.
| Item (Display) | Measurement Item / Range (Display) | Normal Condition |
| Master Cylinder Sensor | Master cylinder pressure sensor 1 reading / min.: 0 V, max.: 5 V | When brake pedal is released: 0.3 to 0.5 V |
Check that the brake fluid pressure value of the master cylinder pressure sensor observed on the intelligent tester changes when the brake pedal is depressed.
- OK:
- When the pedal is depressed, voltage displayed on the intelligent tester increases.
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| OK | |
| 3.READ VALUE OF INTELLIGENT TESTER (STOP LIGHT SWITCH) |
Select the Data List mode on the intelligent tester.
| Item (Display) | Measurement Item / Range (Display) | Normal Condition |
| Stop Lamp SW | Stop light switch / ON or OFF | ON: Brake pedal depressed OFF: Brake pedal released |
Check that the stop light display on the intelligent tester changes when the brake pedal is depressed.
- OK:
- When the brake pedal is depressed, the intelligent tester displays "ON".
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| OK | |
| 4.RECONFIRM DTC |
Turn the engine switch off.
Clear the DTC .
Start the engine.
At a speed of 18 mph (30 km/h) or more, drive the vehicle and perform braking test (decelerate the vehicle by depressing the brake pedal).
Check if the same DTC is recorded .
- Result:
Condition Proceed to DTC (C1246/46) is not output A DTC (C1246/46) is output B
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| A | ||
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