Lexus IS250 IS220d GSE20 ALE20 - BRAKE CONTROL
INSPECT ABS MOTOR1 (FAIL SAFE) RELAY
INSPECT ENGINE ROOM NO. 3 RELAY BLOCK (POWER SOURCE TERMINAL)
INSPECT ENGINE ROOM NO. 3 RELAY BLOCK
CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - ENGINE ROOM NO. 3 RELAY BLOCK)
DTC C0273/13 Open in ABS Motor Relay Circuit
DTC C0274/14 Short to B+ in ABS Motor Relay Circuit
DTC C1361/91 Short Circuit in ABS Motor Fail Safe Relay Circuit
DESCRIPTION
If a DTC of the motor line is stored, the ABS MOTOR1 (fail safe) relay cuts off the power supply to the ABS MOTOR2 relay and performs fail safe.
While any of the ABS, TRC, VSC, or BA is operating, the skid control ECU (housed in the actuator assembly) turns the ABS MOTOR2 relay on and activates the pump motor in the brake actuator.
This code may be stored if the motor relay (+BM) voltage becomes lower than the DTC detecting condition due to insufficient output from the battery or alternator.
| DTC No. | DTC Detection Condition | Trouble Area |
| C0273/13 | When any of the following (1 or 2) is detected: All of the following conditions continue for 0.12 seconds or more. The IG1 terminal voltage is between 9.5 and 17.2 V. ABS, BA, TRC, or VSC are in operation during initial check. Relay contact is open when the relay is ON. All of the following conditions continue for 0.12 seconds. The IG1 terminal voltage is 9.5 V or less. Relay contact remains open when the relay is ON. | ABS1 fuse ABS MOTOR2 relay ABS MOTOR2 relay circuit Brake actuator assembly |
| C0274/14 | When the motor relay is OFF, the ABS MOTOR2 relay remains closed for 4 seconds or more. | ABS1 fuse ABS MOTOR2 relay ABS MOTOR2 relay circuit Brake actuator assembly |
| C1361/91 | Immediately after the engine switch is turned on (IG), the relay contact is closed for 4 seconds when the ABS MOTOR1 (fail safe) relay is OFF. | ABS1 fuse ABS MOTOR1 (fail safe) relay ABS MOTOR1 (fail safe) relay circuit Brake actuator assembly |
WIRING DIAGRAM
INSPECTION PROCEDURE
- NOTICE:
- When replacing the brake actuator assembly, perform zero point calibration .
| 1.INSPECT ABS1 FUSE |
Remove the ABS1 fuse from the engine room No. 1 R/B.
Measure the resistance according to the value(s) in the table below.
- Standard resistance:
Tester Connection Condition Specified Condition ABS1 (50A) fuse Always Below 1 Ω
|
| ||||
| OK | |
| 2.INSPECT ABS MOTOR2 RELAY |
Install the ABS1 fuse.
Remove the ABS MOTOR2 relay.
Measure the resistance according to the value(s) in the table below.
- Standard resistance:
Tester Connection Condition Specified Condition 3 - 5 Always 10 kΩ or higher 3 - 5 Apply B+ between terminals 1 and 2 Below 1 Ω
|
| ||||
| OK | |
| 3.INSPECT ABS MOTOR1 (FAIL SAFE) RELAY |
Remove the ABS MOTOR1 (fail safe) relay.
Measure the resistance according to the value(s) in the table below.
- Standard resistance:
Tester Connection Condition Specified Condition 3 - 5 Always 10 kΩ or higher 3 - 5 Apply B+ between terminals 1 and 2 Below 1 Ω
|
| ||||
| OK | |
| 4.INSPECT ENGINE ROOM NO. 3 RELAY BLOCK (POWER SOURCE TERMINAL) |
Measure the voltage according to the value(s) in the table below.
- Standard voltage:
Tester Connection Condition Specified Condition ABS MOTOR1 (fail safe) relay terminal 5 - Body ground Always 10 to 14 V
|
| ||||
| OK | |
| 5.INSPECT ENGINE ROOM NO. 3 RELAY BLOCK |
Measure the resistance according to the value(s) in the table below.
- Standard resistance:
Tester Connection Condition Specified Condition ABS MOTOR1 (fail safe) relay terminal 3 - ABS MOTOR2 relay terminal 5 Always Below 1 Ω ABS MOTOR1 (fail safe) relay terminal 3 - Body ground Always 10 kΩ or higher
|
| ||||
| OK | |
| 6.CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - ENGINE ROOM NO. 3 RELAY BLOCK) |
Disconnect the skid control ECU connector.
Measure the resistance according to the value(s) in the table below.
- Standard resistance:
Tester Connection Condition Specified Condition A14-2 (BM) - ABS MOTOR2 relay terminal 3 Always Below 1 Ω A14-2 (BM) - Body ground Always 10 kΩ or higher A14-14 (MRF) - ABS MOTOR1 (fail safe) relay terminal 2 Always Below 1 Ω A14-14 (MRF) - Body ground Always 10 kΩ or higher A14-15 (MR) - ABS MOTOR2 relay terminal 2 Always Below 1 Ω A14-15 (MR) - Body ground Always 10 kΩ or higher A14-45 (R+) - ABS MOTOR1 (fail safe) relay terminal 1 Always Below 1 Ω A14-45 (R+) - Body ground Always 10 kΩ or higher
|
| ||||
| OK | |
| 7.RECONFIRM DTC |
Clear the DTC .
Start the engine.
Drive the vehicle at the speed of 4 mph (6 km/h) or more.
Check if the same DTC is recorded .
- HINT:
- Reinstall the relays, connectors, etc. and restore the vehicle to the condition before rechecking for DTCs.
- Result:
Condition Proceed to DTCs (C0273/13, C0274/14 and/or C1361/91) are not output A DTCs (C0273/13, C0274/14 and/or C1361/91) are output B
- HINT:
|
| ||||
| A | ||
| ||