Hyundai Ioniq: AHB(Active Hydraulic Boost) System / Hydraulic Power Unit. Repair procedures
1. | Turn ignition switch OFF and disconnect the negative (-) battery cable. |
2. | Remove the wiring bracket. 
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3. | Remove the brake fluid from the reservoir with a syringe. •
| Do not spill brake fluid on the vehicle, it may damage the paint; if brake fluid does contact the paint, wash it off immediately with water. |
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| To prevent any dust entering in the reservoir, the reservoir cap should be closed again after removing brake fluid. |
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4. | Loosening the flare nut (A) and then disconnect the brake tube. Tightening torque : 13.7 - 16.7 N.m (1.4 - 1.7 kgf.m, 10.1 - 12.3 lb-ft) |

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| Before removing the brake tube, high pressure in an accumulator of PSU should be reduced for safety by conducting "High pressure release mode" of GDS connected to LF HEV. |
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5. | Disconnect the PSU connector. 
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6. | Remove the front sub frame. (Refer to Suspension System - "Sub Frame") |
7. | Loosen the mounting bolt and nut then remove the PSU. Tighten torque : 19.6 - 29.4 N.m (2.0 - 3.0 kgf.m, 14.5 - 21.7 lb-ft) |

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1. | Installation is the reverse of removal. |
2. | Tighten the PSU bracket bolts and brake tube to the specified torque. |
3. | After filling the brake fluid in the reservoir, perform the air bleed. . (Refer to AHB System - "AHB System Air Bleeding") |
4. | Conduct Pressure sensor Calibration. |
5. | Check the brake pedal operation. |
Diagnostic Procedure Using GDS |
The following section describes how to diagnose faults using a diagnostic instrument.
1. | Connect the diagnostic instrument to the self-diagnostic connector (16-pin) beneath the crash pad on the side of driver's seat, and then turn on the ignition to activate the diagnostic instrument. |
2. | In the GDS Vehicle Type Selection menu, select "Vehicle Type" and "ABS/ESC" System, and then opt for "OK." [Pressure Sensor Calibration] 
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3. | Turn ignition switch off and on after calibration procedure. |
4. | Confirm success of calibration. |
Components
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PSU (Presser Source Unit) must not be disassembled.1. Pressure Source Unit (PSU)2. Pressure Source Unit (PSU) connector3...
Other information:
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Safety PrecautionPrecautions To Take Before Servicing High Voltage System
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Since hybrid vehicles contain a high voltage battery, if the high voltage system or vehicles are handled incorrectly, this might lead to a serious accidents like electric shock and electric leakage...
Categories

1. Door lock/unlock button
2. Driver position memory system
3. Side view mirror control switch
4. Central door lock switch
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