C1256

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

DTC C1256/56 - Accumulator Low Pressure

DESCRIPTION

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









INSPECTION PROCEDURE

NOTE: 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 ignition switch off.
(c) Depress the brake pedal more than 20 times.
(d) Turn the ignition switch to ON.
(e) Wait for 99 seconds.
(f) Check if the same DTC is detected Reading and Clearing Diagnostic Trouble Codes.
Result:





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

B -- CHECK FOR INTERMITTENT PROBLEMS
A -- Continue to next step.

2. CHECK HYDRAULIC CIRCUIT
(a) Check the hydraulic circuit On-Vehicle Inspection.
OK:
Hydraulic circuit is normal (No leakage).

NG -- REPAIR HYDRAULIC CIRCUIT
OK -- Continue to next step.

3. READ VALUE USING TECHSTREAM (ACCUMULATOR PRESSURE SENSOR)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON and turn the Techstream main switch ON.
(c) Select "Data List" mode on the Techstream.

ABS/VSC/TRAC





(d) Check that the accumulator's 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 detected Reading and Clearing Diagnostic Trouble Codes.
Result:





B -- CHECK FOR INTERMITTENT PROBLEMS
A -- REPLACE MASTER CYLINDER SOLENOID