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 motor relay 1 for electronically controlled brake system control, and motor relay 2 for ABS control. If either of the relays is malfunctioning, the other is used as a substitute.
| DTC Code | INF Code | DTC Detection Condition | Trouble Area |
|---|---|---|---|
| C1252/52 | 130 | Motor relay is on for at least 3 minutes. |
|
| C1253/53 | 134 | MTT input is less than 3.5 V for at least 1 second when linear solenoid power source voltage 1 (BS1) is 9.5 V or more, either +BI1 or +BI2 voltage is 7 V or more, and motor relay 1 is on. |
|
| ↑ | 138 | MTT input is less than 3.5 V for at least 1 second when linear solenoid power source voltage 2 (BS2) is 9.5 V or more, either +BI1 or +BI2 voltage is 7 V or more, and motor relay 2 is on. |
|
| ↑ | 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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