COMPONENTS
ILLUSTRATION

InstallationPower Supply Drive Circuit (C1257)
DESCRIPTION
The motor relay (semiconductor relay) is built into the hydraulic brake booster
and drives the pump motor based on a signal from the skid control ECU (master cylinder
solenoid).
DTC No.
DTC Detecting Condition
Trouble Areas
C1257
...
Brake Switch "A" Circuit Open (P057113)
DESCRIPTION
When the brakes are applied by the dynamic radar cruise control system, the skid
control ECU (master cylinder solenoid)*1 or skid control ECU (brake actuator assembly)*2
operates the stop light switch assembly (stop light relay) to illuminate the stop
lights.
If the ECM receives ...
Tire Pressure Monitor ECU Communication Stop Mode
DESCRIPTION
Detection Item
Symptom
Trouble Area
Tire Pressure Monitor ECU Communication Stop Mode
Either condition is met:
Communication stop for "Tire Pressure2" is indicated on the
"Communication Bus C ...