| Checking pressures on vehicles with an electrically driven air conditioner compressor (vehicles with a high-voltage system) |
WARNING | Safety hazard: the engine can start unexpectedly. |
| Before carrying out general work on a vehicle with high-voltage electrical system, switch off the ignition and remove the ignition key from the vehicle. |
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WARNING | Working on vehicles with high-voltage wiring: |
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| Do not support yourself or tools on high-voltage wiring or associated components --> this can damage the insulation. |
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| High-voltage wiring must not be excessively bent or kinked --> this can damage the insulation. |
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| The round high-voltage connectors are colour-coded with an external coloured ring and are provided with mechanical coding or guide lugs. It is important to observe this coding when joining up the round high-voltage connectors, otherwise the connectors can be damaged. |
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DANGER! | Risk of fatal injury if high-voltage components are damaged. |
| Observe the following when working in the vicinity of high-voltage components or wiring: |
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| It is not permitted to use cutting or forming tools, other sharp-edged tools or heat sources such as welding, brazing, soldering, hot air or thermal bonding equipment. |
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| Before starting work, visually inspect the high-voltage components in the areas involved. |
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| Before working in the engine compartment, visually inspect the power electronics -JX1-, electric drive motor -V141-, air conditioner compressor -V470- and high-voltage wiring. |
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| Before working on the vehicle underbody, visually inspect the high-voltage wiring and covers. |
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| Before working on the rear section of the vehicle, visually inspect the high-voltage wiring and the electro-box with the maintenance connector for high-voltage system - TW -. |
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| Visually inspect all potential equalisation lines. |
| Check the following when making the visual inspection: |
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| There must be no external damage on any component. |
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| The insulation of the high-voltage wiring and potential equalisation lines must not be damaged. |
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| There must be no unusual deformation of the high-voltage wiring. |
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| All high-voltage components must be identified by a red warning sticker. |
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| If work is necessary in the vicinity of high-voltage system components, perform a visual inspection of the high-voltage components and wiring to check for damage → Chapter and note → Electrical system; Rep. gr.93. |
Note | The work on the refrigerant circuit using the air conditioner service station (here: checking pressure) described in the following can only be carried out when the vehicle's drive system is active; if necessary, re-energise the high-voltage system. |
| Re-energising high-voltage system |
DANGER! | Voltage can cause fatal injury. |
| Danger of severe or fatal injuries from electric shock. |
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| For reasons of safety, persons with life-preserving or other electronic medical devices in or on their body must not perform any work on the high-voltage system. Such medical devices include internal analgesic pumps, implanted defibrillators, pacemakers, insulin pumps and hearing aids. |
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| The high-voltage system may only be re-energised by a suitably qualified person (Audi high-voltage technician). |
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| The system may only be re-energised using the vehicle diagnostic tester via „Guided Fault Finding“. |
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| The vehicle is then made ready for operation again by the qualified person (Audi high-voltage technician). |
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| The qualified person (Audi high-voltage technician) marks the vehicle by attaching the appropriate warning signs. |
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| Re-energise high-voltage system: |
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| Connect vehicle diagnostic tester |
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| Select Guided Fault Finding mode |
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| Using the Go to key, select the following menu items in succession |
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| Function/component selection |
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| Self-diagnosis compatible systems |
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| 8C - Hybrid battery management -J840 |
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| 8C - Hybrid battery management, functions |
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| 51 - Re-energise high-voltage system (Rep. gr. 93) |
DANGER! | When working on a vehicle with the ignition switched on or while the drive system is active, the engine can start unexpectedly and exhaust fumes can cause a health hazard in closed rooms. Moving parts can trap or draw in parts of the body and/or clothing (safety hazard). |
| Before switching on the ignition, perform the following steps: |
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| Move selector lever to position P |
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| Connect battery charger (e.g. -VAS 5095A-) to jump-start connections of 12 V electrical system |
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| For test and measurement work that requires the vehicle's drive system to be active or the ignition to be switched on, move the selector lever to position „P“, activate the parking brake and arrange the tools needed so that they cannot come into contact with moving components of the engine and so that they cannot even come near to components that turn when the engine is running. |
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| Move the selector lever to position „P“ and activate the parking brake before performing test and measurement work for which the ignition must be switched on but where the vehicle's drive system does not need to be active. |
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| The status of the drive system is shown by the control unit in dash panel insert -J285- via the „power meter“ → Owner's Manual. |
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| Activating and deactivating drive system → Owner's Manual (note display of control unit in dash panel insert -J285-). |
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| Connect air conditioner service station → Chapter. |
Note | If problems are only encountered at one evaporator on vehicles fitted with two evaporators (one in air conditioning unit and one in battery cooling module), check whether the pressures in the refrigerant circuit are OK. Check for cross-sectional restriction or blockage of the pipe connection between the problematic evaporator and the outgoing pipe connection at the refrigerant pipe distribution point. If no fault is found, discharge the refrigerant circuit and re-fill it with the specified quantity of refrigerant. Then check the pressures and the cooling output of the air conditioner again. If the problem persists, check/renew the following components: If the problem only occurs at the evaporator in the air conditioning unit, check the refrigerant shut-off valve 1 for hybrid battery -N516- (the valve is open when it is not actuated and allows refrigerant to flow through). Renew the expansion valve at the evaporator in the air conditioning unit if no fault is found at -N516-. If the problem only occurs at the evaporator in the battery cooling module, check the actuation of the refrigerant shut-off valve 2 for hybrid battery -N517- at the expansion valve on the evaporator in the battery cooling module (the valve is closed when it is not actuated and does not allow refrigerant to flow through) → Air conditioning; Rep. gr.87 (vehicle-specific Workshop Manual). |
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| Check the pressures in the refrigerant circuit (with the air conditioner service station) with the ignition switched off → Chapter. |
| The pressures with the ignition switched off correspond to the specifications. |
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| Move the selector lever to position „P“ and activate the parking brake before performing test and measurement work for which the ignition must be switched on but where the vehicle's drive system does not need to be active. |
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| On vehicles with a high-voltage system, the engine does not have to be running to check the pressures in the refrigerant circuit. |
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| The status of the drive system is shown by the control unit in dash panel insert -J285- via the „power meter“ → Owner's Manual. |
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| Activate READY (and heed the display in the control unit in dash panel insert -J285-) → Owner's manual. |
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| Switch on the air conditioner. |
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| Observe the pressure reading (e.g. pressure gauge) of the air conditioner service station. |
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| The electrically driven air conditioner compressor is actuated by the vehicle electronics. The engine speed has no influence on the cooling output of the air conditioner. |
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| When the vehicle is stationary or only moving slowly (up to a vehicle speed of approx. 45 km /h), the air conditioner compressor is not actuated at the maximum specified speed (of approx. 8500 rpm) (the air conditioner compressor speed is limited to approx. 5000 rpm). |
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| The pressures must be measured at the service connections; the fitting locations of these connections are vehicle-specific → Air conditioning; Rep. gr.87 (vehicle-specific workshop manual). |
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| Specifications for pressures in refrigerant circuit → Chapter |
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