Component Location
General Description
The HECU supplies battery power to the electric motor with a motor relay which is controlled by the Electronic Control Unit(ECU). The electric motor pump supplies hydraulic pressure to all wheel brake calipers by operating the piston inside the pump.
DTC Description
The HECU monitors the pump motor relay or fuse open, open or short in motor or motor lock and then sets this code if a malfunction is detected. Warning lamp is turned OFF unless fault is detected any more when the IG KEY is turned ON again, and wheel speed is more than 15 Km/h.
DTC Detecting Condition
Item | Detecting Condition | Possible cause |
DTC Strategy | Voltage monitoring
| Open or short of power supply circuit (ABS1)
Faulty HECU
|
Case1 (Stop monitor) | Monitoring Period | Stop monitor is active if the pump is off i.e. not actuation and no Slowdown.
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Enable Conditions | A failure is detected if the pump motor voltage > 2.0V for more than 1s.
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Fail Safe | The return pump does not work correct.
The ABS/ESP functions are inhibited, reduced function of the EBD system.
The ABS/EBD/ESP warning lamps are activated.
|
Case2 (Pump run monitor) | Monitoring Period | The monitor is active if the pump is switched on
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Enable Conditions | A failure is detected if the pump motor voltage < (battery voltage - 4.0V)for more than 100ms.
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Fail Safe | Pressure decrease (outlet valve) is no longer possible.
The ABS/ESP functions are inhibited, reduced function of the EBD system.
The ABS/EBD/ESP warning lamps are activated.
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Case3 (Pump slowdown monitor) | MonitoringPeriod | Monitor is always active in the transition "pump on -> pump off".
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Enable Conditions | After the end of the actuation of the motor relay has, the pump motor is still in motion and is generating a Voltage during it.s slowdown. The generated UM is monitored for a certain time on high level. The time depends on the supply voltage and is in the range of t = 30ms to t = 125ms. If the slow down condition isn.t met, the pump is activated again (see actuation times below) and the slowdown time is measured again. This is repeated for maximum n = 3 times. If, after the last pump activation, the pump motor slowdown time is still to short, a failure is detected.Actuation times: 1st actuation: 200 ms 2nd actuation: 1000 ms 3rd actuation: 3000 ms
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Fail Safe | Pressure decrease (outlet valve) is no longer possible.
The ABS/ESP functions are inhibited, reduced function of the EBD system.
The ABS/EBD/ESP warning lamps are activated.
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Diagnostic Circuit Diagram