General Information

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Read and follow all of the supplemental warnings for all work performed on vehicles with the high voltage system. Refer to WARNINGS WHEN WORKING ON VEHICLES WITH HIGH VOLTAGE SYSTEM .

WARNING:

Risk of unintended engine start

The ignition must be turned off and the ignition key must remain outside of the vehicle when working on vehicles with a high voltage system.

WARNING:

Handling high voltage cables:

Do not stand on or place tools on high voltage cables and their components as it may damage the cable insulation.
Never bend or kink high voltage cables forcefully as it may damage the cable insulation.
The round high voltage connectors are color coded with an external color ring and are mechanically coded using the guide- or code tabs. Always make certain that the coding matches when connecting the round connector in order to avoid any mechanical damage the high voltage connector.

CAUTION:

There is a risk of electrocution from damaged high voltage components.

Observe the following when working around high voltage components and high voltage wires:

Never work around high voltage components and cables with cutting, deformed, or sharp edged tools, or heat sources such as welding or soldering tools, heated air, and thermal glue.
Inspect the high voltage components visually before beginning.
Perform a visual inspection of the Electric Drive Power and Control Electronics -JX1-, the Electro-Drive Drive Motor -V141-, the Electrical A/C Compressor -V470- and the high voltage lines when working in the engine compartment.
Perform a visual inspection of the high voltage lines and covers when working on the underbody.
Perform a visual inspection of the high voltage lines and the Electrobox with the High Voltage System Maintenance Connector -TW- when working in the luggage compartment.
Perform a visual inspection on all of the potential equalization cables.

Observe the following items when performing the visual inspection:

The components do not display any signs of external damage.
The high voltage cable insulation and the potential equalization cables are not damaged.
The high voltage cables do not display any abnormal deformations.
Every high voltage component is marked with a red warning label.

If it is necessary to perform work in the vicinity of high voltage components, perform a "visual inspection" of the high voltage components and cables for damages (refer to PERFORMING A VISUAL INSPECTION OF DAMAGE TO HIGH VOLTAGE COMPONENTS AND CABLES ) and follow the "warnings when working on the high voltage system". Refer to HIGH VOLTAGE SYSTEM GENERAL WARNINGS for CAEB & CAED Engines, HIGH VOLTAGE SYSTEM GENERAL WARNINGS for CPMA & CPMB Engines or HIGH VOLTAGE SYSTEM .

If it is necessary to perform work on the high voltage components, disable the high voltage system. Refer to HIGH VOLTAGE SYSTEM GENERAL WARNINGS for CAEB & CAED Engines, HIGH VOLTAGE SYSTEM GENERAL WARNINGS for CPMA & CPMB Engines or HIGH VOLTAGE SYSTEM and read and follow the "high voltage electrical system general warnings" Refer to HIGH VOLTAGE SYSTEM GENERAL WARNINGS for CAEB & CAED Engines, HIGH VOLTAGE SYSTEM GENERAL WARNINGS for CPMA & CPMB Engines or HIGH VOLTAGE SYSTEM .

NOTE:

The following steps using the A/C service station (checking pressures) on the refrigerant circuit can only be performed while the drive ready mode is active. If necessary, restart the high voltage system.

Restart the high voltage system

CAUTION:

Risk of electrocution

Death or serious bodily injury by electric shock

The high voltage system may only be restarted by qualified personal (Audi high voltage technicians).
Make sure the vehicle is energized using the "Guided Fault Finding " on the Vehicle Diagnostic Tester.
The qualified personal (Audi high voltage technician) restarts the vehicle.
The Audi high voltage technician should put a sign on the vehicle to identify it as a high voltage vehicle.

NOTE:

Restart the high voltage system:

Connect the Vehicle Diagnostic Tester.

Select the Guided Fault Finding mode.

Using the GO TO button, select the following menu commands

Function/Component Selection

Body

Electrical Equipment

OBD-capable systems

8C - Battery Regulation Control Module -J840

8C - Battery Regulation Control Module, functions

51 - High voltage restart (Repair Group 93)

CAUTION:

The engine may start unexpectedly when performing work while the ignition is turned on or when the ready mode is activated and may cause poisoning in enclosed spaces. Be aware of body limbs and/or clothing when clamping or pulling.

Perform the following steps before turning on the ignition:

Move the selector lever into position P.
Activate the parking brake.
Switch off ignition.
Open the engine hood.
Connect the charging unit for example Battery Charger VAS 5095A to the battery jump start terminal for the 12V vehicle electrical system
Switch on the ignition.

-- Charge the vehicle battery, for example, using the Battery Charger VAS5904 in the battery support mode to minimize the number of automatic starts during the test- and measuring procedures while the ready mode is active. Refer to Battery Charger VAS5095A and Refer to HIGH VOLTAGE SYSTEM GENERAL WARNINGS for CAEB & CAED Engines, HIGH VOLTAGE SYSTEM GENERAL WARNINGS for CPMA & CPMB Engines or HIGH VOLTAGE SYSTEM .

-- Move the selector level into position "P", activate the parking brake and arrange the necessary tools for testing and measuring procedures that require the ready mode to be active or that require the ignition to be on, so that they cannot come into contact with the turning components in the engine and so that they are not in the vicinity of the turning components of a running engine.

NOTE:

Also move the selector lever into position "P" and activate the parking brake for testing and measuring procedures which require the ignition to be on, but do not require the ready mode to be active.

The ready mode is displayed in the Instrument Cluster Control Module -J285- above the "powermeter". Refer to Owner's Manual.

Activate and deactivate the ready mode. Refer to Owner's Manual (consult the display in the Instrument Cluster Control Module -J285-).

-- Turn off the ignition.

NOTE:

If a malfunction occurs at only one evaporator in vehicles with two evaporators (one evaporator in the A/C unit and the other in the battery cooling module or in the high voltage battery heat exchanger), also check pressures in the refrigerant circuit, are these OK? Check the line connection between the evaporator in question and the exit of line connection at distribution point of refrigerant lines (for constriction or blockage, for example in the refrigerant line restrictor to the high voltage battery heat exchanger). If no malfunction can be detected, discharge the refrigerant circuit and charge it with the specified refrigerant quantity. Then check the pressures and A/C system cooling output again; if the malfunction occurs again, check / replace the following components: if the complaint is only occurs at the evaporator in the A/C unit, the shut-off valve is prematurely switched by the evaporator (for example Hybrid Battery Refrigerant Shut-Off Valve 1 -N516- or the Heater and A/C Unit Refrigerant Cut-Off Valve -N541-). This component is open when it is not activated and allows the refrigerant to flow through. Replace the expansion valve on the evaporator in the A/C unit, if no fault can be found on the Hybrid Battery Refrigerant Shut-Off Valve 1 -N516- / Heater and A/C Unit Refrigerant Cut-Off Valve -N541-. If a malfunction occurs only on the evaporator for the cooling the high voltage components (for example in the battery cooling module), check the activation of the Hybrid Battery Refrigerant Shut-Off Valve 2 -N517- on the evaporator expansion valve in the battery cooling module (it is closed when it is not activated and does not allow the refrigerant to flow through). If the malfunction only occurs on the high voltage battery heat exchanger, check the High Voltage Battery Heater Core Refrigerant Cut-Off Valve -N542- (it is open when it is not activated and allows the refrigerant to flow through) and the restrictor installed in the refrigerant line. Refer to OVERVIEW - REFRIGERANT CIRCUIT (vehicle-specific repair information).

-- With the ignition switched off, check the pressure in the refrigerant circuit (using the service station). Refer to REFRIGERANT CIRCUIT, CHECKING PRESSURE WITH SERVICE STATION .

The pressures with the ignition turned off meet the specifications.

NOTE:

Also move the selector lever into position "P" and activate the parking brake for testing and measuring procedures which require the ignition to be on, but do not require the ready mode to be active.

The engine must not be running when checking the pressures in the refrigerant circuit on vehicles with a high voltage system.

The ready mode is displayed in the Instrument Cluster Control Module -J285- above the "power meter". Refer to Owner's Manual.

Activate the ready mode (and observe the display in the Instrument Cluster Control Module -J285-). Refer to the Owner's Manual.

-- Activate the drive ready mode. Refer to the Owner's Manual.

-- Switch on the A/C system.

-- Observe the pressure gauge of the service station.

NOTE:

The activation of the electrically driven A/C compressor occurs from the vehicle electrical system. The engine RPM does not have any effect on the A/C cooling output.

The A/C compressor is not actuated at the maximum specified speed (of approximately 8500/min) on a stationary or slow moving vehicle (up to a speed of approximately 45km/h) (the A/C compressor speed is limited to approximately 5000/min).

The activation of the electrically driven A/C compressor can be monitored by the "Guided Fault Finding " using the Vehicle Diagnostic Tester Function for A/C System and the Battery Regulation.

Pressures must be measured at service connections; component locations of these connections are vehicle-specific. Refer to OVERVIEW - REFRIGERANT CIRCUIT (vehicle-specific repair information).