DESCRIPTION
The motor relay (semiconductor relay) is built into the master cylinder solenoid and drives the pump motor based on a signal from the skid control ECU.
DTC Code |
DTC Detection Condition |
Trouble Area |
---|---|---|
C1257 |
There is an open in the motor system circuit (motor input circuit). |
Master cylinder solenoid (Skid control ECU) |
CAUTION / NOTICE / HINT
NOTICE:
When replacing the master cylinder solenoid, perform calibration (See page
).
PROCEDURE
1. |
CHECK PUMP MOTOR OPERATION |
(a) Turn the ignition switch off.
(b) Disconnect the A6 skid control ECU connector.
(c) Depress the brake pedal more than 40 times.
(d) Turn the ignition switch to ON.
(e) Check pump motor operation.
OK:
Pump motor operates normally.
NG | ![]() |
REPLACE MASTER CYLINDER SOLENOID |
|
2. |
RECONFIRM DTC |
(a) Turn the ignition switch off.
(b) Reconnect the A6 skid control ECU connector.
(c) Turn the ignition switch to ON.
(d) Clear the DTCs (See page ).
(e) Turn the ignition switch off.
(f) Check if the same DTC is output (See page
).
Result |
Proceed to |
---|---|
DTC is output |
A |
DTC is not output |
B |
A | ![]() |
REPLACE MASTER CYLINDER SOLENOID |
B | ![]() |
USE SIMULATION METHOD TO CHECK |
Data List / Active Test
DATA LIST / ACTIVE TEST
1. DATA LIST
HINT:
Using the Techstream to read the Data List allows the values or states of switches,
sensors, actuators and other items to be read without removing any parts. This non-intrusive
inspection can be very useful bec ...
Certification ECU Power Source Circuit
DESCRIPTION
This circuit provides power to the certification ECU.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
Inspect the fuses for circuits related to this system before performing the following
inspection procedure.
PROCEDURE
1.
...