DTC C1225/25 SM Solenoid Circuit: Wiring Diagram

WARNING: This page is about a different car, the 2006 Lexus IS 350. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Wiring Diagram

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NOTE: When replacing the skid control ECU, perform zero point calibration (See CALIBRATION ).

INSPECT BRAKE ACTUATOR ASSEMBLY

Disconnect the brake actuator connector.

Measure the resistance according to the value(s) in the table below.

Standard resistance

TESTER CONNECTION AND SPECIFIED CONDITION CHART

Tester Connection	Condition	Specified Condition
13 (SM1+) - 14 (SM1-)	Always	8.1 to 9.1 Ω at 25°C (77°F)
14 (SM1-) - Body ground	Always	10 kΩ or higher
15 (SM2+) - 16 (SM2-)	Always	8.1 to 9.1 Ω at 25°C (77°F)
16 (SM2-) - Body ground	Always	10 kΩ or higher

Fig 2: Inspecting Brake Actuator Assembly

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG : REPLACE BRAKE ACTUATOR ASSEMBLY

OK : GO TO NEXT STEP

CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - BRAKE ACTUATOR ASSEMBLY)

Disconnect the skid control ECU connector.

Measure the resistance according to the value(s) in the table below.

Standard resistance

TESTER CONNECTION AND SPECIFIED CONDITION CHART

Tester Connection	Condition	Specified Condition
J78-25 (SM1+) - A13-13 (SM1+)	Always	Below 1 Ω
J78-25 (SM1+) - Body ground	Always	10 kΩ or higher
J78-12 (SM1-) - A13-14 (SM1-)	Always	Below 1 Ω
J78-12 (SM1-) - Body ground	Always	10 kΩ or higher
J78-11 (SM2+) - A13-15 (SM2+)	Always	Below 1 Ω
J78-11 (SM2+) - Body ground	Always	10 kΩ or higher
J78-24 (SM2-) - A13-16 (SM2-)	Always	Below 1 Ω
J78-24 (SM2-) - Body ground	Always	10 kΩ or higher

Fig 3: Checking Harness And Connector (Skid Control ECU - Brake Actuator Assembly)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG : REPAIR OR REPLACE HARNESS OR CONNECTOR

OK : GO TO NEXT STEP

RECONFIRM DTC

Reconnect the skid control ECU connector and the brake actuator connector.
Clear the DTC (See DTC CHECK / CLEAR ).
Start the engine.

Check if the same DTC is recorded (See DTC CHECK / CLEAR ).

Result

CONDITION CHART

Condition	Proceed to
DTC (C1225/25) is not output	A
DTC (C1225/25) is output	B

HINT:

If the normal system code is output (the trouble code is not output), slightly jiggle the connectors, wire harness, and fuses of the skid control ECU and brake actuator assembly. Make sure that no DTCs are output.
If any DTCs are output while jiggling a connector or wire harness of the skid control ECU and brake actuator assembly, inspect and repair the connector or wire harness.

B : REPLACE SKID CONTROL ECU

A : USE SIMULATION METHOD TO CHECK