DTC C1252/52: Brake Booster Pump Motor on Time Abnormally Long; DTC C1253/53: Pump Motor Relay Malfunction: Description
The skid control ECU detects decreases in the accumulator pressure according to the data from the accumulator pressure sensor, and then starts and stops the pump motor by operating the motor relay.
The skid control ECU usually drives the ABS motor relay (ABS MTR) for electronically controlled brake system control, and the ABS motor relay 2 (ABS MTR2) for ABS control. If either is of them malfunctioning, the other will substitute.
| DTC Code | Information Code | DTC Detection Condition | Trouble Area |
|---|---|---|---|
| C1252/52 | 130 | Motor relay is on for at least 3 minutes. |
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| C1253/53 | 134 | When the linear solenoid power supply 1 (BS1) is 9.5 V or more, either of +BI1 or +BI2 voltage is 7 V or more, and the motor relay 1 is on, MTT input of less than 3.5 V continues for 1 second or more. |
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| ↑ | 138 | When the linear solenoid power supply 2 (BS2) is 9.5 V or more, either of +BI1 or +BI2 voltage is 7 V or more, and the motor relay 2 is on, MTT input of less than 3.5 V continues for 1 second or more. |
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| ↑ | 140 | MTT input is 3.5 V or more for at least 2 seconds when motor relay 1 and 2 are off. |
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