DTC C1305/21 Solenoid Identification Circuit

DESCRIPTION

The skid control ECU receives solenoid identification signals from terminals SSEL and SEL2. The ECU specifies control characteristics of the brake actuator by monitoring the difference in the holding solenoid (FRA, FLA, RRA and RLA) current, which is caused by characteristics of each actuator.

Dtc C1305/21 Solenoid Identification Circuit. BRAKE CONTROL. Lexus IS250 IS220d GSE20 ALE20

DTC No.	DTC Detection Condition	Trouble Area
C1305/21	Immediately after the engine is started, an open or short in the solenoid characteristics identification circuit continues for 0.21 seconds or more.	Internal solenoid identification circuit of the brake actuator assembly Skid control ECU

WIRING DIAGRAM

Dtc C1305/21 Solenoid Identification Circuit. BRAKE CONTROL. Lexus IS250 IS220d GSE20 ALE20

INSPECTION PROCEDURE

NOTICE:

When replacing the skid control ECU, perform zero point calibration and store system information .

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

Dtc C1305/21 Solenoid Identification Circuit. BRAKE CONTROL. Lexus IS250 IS220d GSE20 ALE20

Disconnect the skid control ECU connector and the brake actuator connector.

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

Standard resistance:
LHD:

Tester Connection	Condition	Specified Condition
A35-14 (SSEL) - A13-44 (SSEL)	Always	Below 1 Ω
A35-14 (SSEL) - Body ground	Always	10 kΩ or higher
A35-16 (SEL2) - A13-41 (SEL2)	Always	Below 1 Ω
A35-16 (SEL2) - Body ground	Always	10 kΩ or higher

RHD:

Tester Connection	Condition	Specified Condition
J98-14 (SSEL) - A13-44 (SSEL)	Always	Below 1 Ω
J98-14 (SSEL) - Body ground	Always	10 kΩ or higher
J98-16 (SEL2) - A13-41 (SEL2)	Always	Below 1 Ω
J98-16 (SEL2) - Body ground	Always	10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

2.INSPECT SKID CONTROL ECU (IDENTIFICATION OUTPUT)

Reconnect the skid control ECU connector and the brake actuator connector.

Start the engine.

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

Standard voltage:
LHD:

Tester Connection	Condition	Specified Condition
A35-14 (SSEL) - Body ground	Low (Normal)	0 V
A35-14 (SSEL) - Body ground	Middle	3.7 to 8.26 V
A35-14 (SSEL) - Body ground	High	7.8 to 14 V
A35-16 (SEL2) - Body ground	Low (Normal)	0 V
A35-16 (SEL2) - Body ground	Middle	3.7 to 8.26 V
A35-16 (SEL2) - Body ground	High	7.8 to 14 V

RHD:

Tester Connection	Condition	Specified Condition
J98-14 (SSEL) - Body ground	Low (Normal)	0 V
J98-14 (SSEL) - Body ground	Middle	3.7 to 8.26 V
J98-14 (SSEL) - Body ground	High	7.8 to 14 V
J98-16 (SEL2) - Body ground	Low (Normal)	0 V
J98-16 (SEL2) - Body ground	Middle	3.7 to 8.26 V
J98-16 (SEL2) - Body ground	High	7.8 to 14 V

OK:
Input voltage of SSEL and SEL2 is the same under all conditions.

NG

REPLACE BRAKE ACTUATOR ASSEMBLY

OK

3.RECONFIRM DTC

Turn the engine switch off.

Clear the DTC .

Drive the vehicle at the speed of 15 mph (24 km/h) or more.

Check if the same DTC is recorded .

Result:
Condition Proceed to
DTC (C1305/21) is not output A
DTC (C1305/21) 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

LEXUS IS250, IS220d / GSE20 ALE20

BRAKE CONTROL

Lexus IS250 IS220d GSE20 ALE20

VEHICLE STABILITY CONTROL SYSTEM w/ VDIM