C1256

BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: C1256/56: Accumulator Low Pressure


DESCRIPTION

The accumulator pressure sensor is connected to the skid control ECU in the master cylinder solenoid.









INSPECTION PROCEDURE

NOTICE:
When replacing the master cylinder solenoid, perform zero point calibration Programming and Relearning.

HINT
When C1251/51, C1253/53, or C1254/54 is output together with C1256/56, inspect and repair the trouble area indicated by C1251/51, C1253/53, or C1254/54 first.

PROCEDURE

1. RECONFIRM DTC

(a) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(b) Turn the engine switch off.

(c) Depress the brake pedal more than 20 times.

(d) Turn the engine switch on (IG).

(e) Wait for 99 seconds.

(f) Check if the same DTC is output Reading and Clearing Diagnostic Trouble Codes.

Result





HINT
Excessive brake pedal operation results in abnormal accumulator pressure consumption. This is normal.

B -- USE SIMULATION METHOD TO CHECK How To Proceed With Troubleshooting
A -- Continue to next step.

2. CHECK HYDRAULIC CIRCUIT

(a) Check the hydraulic circuit Description and Operation.

OK:

Hydraulic circuit is normal (No leakage).

NG -- REPAIR HYDRAULIC CIRCUIT Description and Operation
OK -- Continue to next step.

3. READ VALUE USING TECHSTREAM (ACCUMULATOR SENSOR)

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG) and turn the Techstream on.

(c) Enter the following menus: Chassis / ABS/VSC/TRAC / Data List.

ABS/VSC/TRAC





(d) Check that the accumulator output value is normal.

OK:

Accumulator pressure sensor value is normal.

NG -- REPLACE MASTER CYLINDER SOLENOID
OK -- Continue to next step.

4. RECONFIRM DTC

(a) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(b) Check if the same DTC is output Reading and Clearing Diagnostic Trouble Codes.

Result





B -- USE SIMULATION METHOD TO CHECK How To Proceed With Troubleshooting

A -- REPLACE MASTER CYLINDER SOLENOID