Automatic A/c-Heater System Audi TT 8N

SPECIFICATIONS

SPECIFICATIONS

DESCRIPTION

When A/C system is set to AUTO mode, air temperature, air flow and air distribution are regulated automatically to achieve and maintain the desired passenger compartment temperature as quickly as possible. The system takes into account the outside air temperature and makes the needed adjustments as necessary.

The A/C-heater system automatically maintains temperatures from 64°F (18°C) to 84°F (29°C). If a temperature greater than 84°F (29°C) is selected, the word HI appears in temperature display. If temperature less than 64°F (18°C) is selected, the word LO is displayed. Selection of these temperatures overrides automatic climate control system.

Scheme 1

A/C-Heater Control Panel

A/C-heater control panel has a digital microprocessor that compares values from various sensors. Microprocessor then activates appropriate flap motor and A/C compressor clutch to maintain desired temperature. A/C clutch, blower speed, temperature/blend air door position, and mode doors are all controlled by A/C-heater control panel.

Air Distribution

Three push buttons control air distribution. (Scheme 1) When selected, uppermost air distribution push button directs air to windows. When middle air distribution push button is selected, air is directed to dashboard outlets. When lowermost air distribution push button is selected, air is directed to footwells.

Automatic Mode

In AUTO setting, air temperature, air delivery, and air distribution are regulated automatically to achieve and maintain desired interior temperature. All previously selected settings are cancelled.

Blower Speed Settings

Blower speed fan switch can be used to raise or lower blower speed in all operating modes. Turning blower speed fan switch toward plus (+) is used to raise blower speed. Turning blower speed fan switch toward minus (-) lowers blower speed.

Compressor On/Off Button

Temperature control switch is depressed to activate, and pulled out to disengage A/C compressor.

Defrost Mode

In this setting, blower operates at highest speed and temperature is automatically regulated. All air is directed toward windshield and side windows.

A/C HIGH-PRESSURE SENSOR

Note. A/C high-pressure sensor may be removed without discharging A/C system.

A/C high-pressure sensor sends a varying pulse width signal to coolant fan control module based on system pressure. If pulse width is between 13-78 percent, coolant fan control module sends positive signal to A/C-heater control panel to engage A/C compressor. If pulse width is outside of specified range, A/C compressor is turned off.

PRESSURE RELIEF VALVE

Pressure relief valve is mounted on compressor. At about 558 psi (39.24 kg/cm 2 ), valve opens to vent excessive pressure. When system pressure is reduced to about 435-508 psi (30.58-35.7 kg/cm 2 ), valve closes to prevent total refrigerant loss.

A/C-HEATER CONTROL PANEL CODING

Note. Basic setting procedure must be performed each time A/C-heater control panel is coded. See BASIC SETTING . Verify engine and A/C compressor type, code A/C-heater control panel and perform basic setting. Always verify coding of removed and replacement A/C-heater control panel.

Ensure scan tool is in A/C HEATING ELECTRONICS function. With RAPID DATA TRANSFER displayed on scan tool, press "0" and "7" buttons to select CODE CONTROL UNIT function. Press "Q" button to confirm input. Press right arrow button. Enter code "00 140" for USA, 4-cylinder, left hand drive, gas engine. Press "Q" button to enter input. Perform BASIC SETTING.

SELF-DIAGNOSTICS

Note. Scan Tool (VAG 1551 or VAG 1552) must be used to make full use of the system's self-diagnostic capabilities.

A/C-heater control panel receives input information from various electrical and electronic sensors. This information is processed by control panel according to specified values. Corresponding output signals are provided that control electrical actuators. Control panel is controlled by an internal microprocessor with On-Board Diagnostic (OBD) capability. If faults are detected, Diagnostic Trouble Codes (DTCs) are stored in DTC memory. Stored DTCs are identified using either VAG 1551 or VAG 1552 scan tool.

If a fault exists for a certain time, it is stored as a STATIC FAULT. If a static fault is no longer present, it is stored as a SPORADIC FAULT and the reference "SP" appears on the upper right of scan tool display or print out. Before replacing a component suspected of malfunctioning, check all related wiring, connections, harness connectors and ground connections using wiring diagram. Output Diagnostic Test Mode (DTM), basic setting, A/C control panel identification and coding functions are also possible.

RETRIEVING & CLEARING DIAGNOSTIC TROUBLE CODES

Note. DTC output is possible only if ignition is on or engine is operating and engine speed is less than 3000 RPM (if engine speed is higher, output is possible only for a limited time or is terminated).

Ensure battery is fully charged. Ensure all fuses are okay. Ensure ground connections at engine and transmission are clean and tight. Locate Data Link Connector (DLC), just left of steering column. Turn ignition off. When using VAG 1551 scan tool, use Adapter Cable (VAG 1551/3). When using VAS 5051/1552 scan tool, use Adapter Cable (VAS 5051/1) to connect scan tool to DLC.

Note. The following procedures is for VAG 1551 scan tool only. For other scan tools, see operating instructions in scan tool owner's manual.

1. To check DTC memory, press buttons "0" and "8" to select A/C HEATING ELECTRONICS function (address word 08). Advance program until SELECT FUNCTION XX appears on display. Turn scan tool printer on by pressing PRINT button (indicator light in button illuminates).
2. Press buttons "0" and "2" to select CHECK DTC MEMORY. See «SCAN TOOL DIAGNOSTIC FUNCTIONS»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system) table. Press "Q" button to confirm input. Number of stored DTCs are displayed and printed out. Press right arrow button. If NO DTC RECOGNIZED is displayed, program returns to starting position after right arrow button is pressed.

SCAN TOOL DIAGNOSTIC FUNCTIONS

DTC IDENTIFICATION

BASIC SETTING

1. Connect scan tool and enter A/C HEATING ELECTRONICS function (address word 08). Move forward in program until SELECT FUNCTION XX appears in display. Switch printer on by pressing PRINT button.
2. Check Diagnostic Trouble Code (DTC) memory. See «RETRIEVING & CLEARING DIAGNOSTIC TROUBLE CODES»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system__retrieving-clearing-diagnostic-trouble-codes) . Repair A/C system malfunctions (if any).
3. Erase DTC memory, and check coding of A/C-heater control panel and re-code if necessary. See «A/C-HEATER CONTROL PANEL CODING»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system__ac-heater-control-panel-coding) under PROGRAMMING.
4. Ensure scan tool is in A/C HEATING ELECTRONICS function. With RAPID DATA TRANSFER displayed on scan tool, press "0" and "4" buttons to select 04-BASIC SETTING function. Press "Q" button to confirm input.
5. With START BASIC SETTING and INPUT DISPLAY NUMBER XXX displayed on scan tool, press "0", "0" and "1" buttons (001). Press "Q" button to confirm input.
6. The following flap motors are actuated in sequence and end positions are stored in A/C control panel: temperature regulator flap motor, central flap motor, footwell/defroster flap motor and airflow flap motor. End positions are determined from resistance values of potentiometers installed in flap motors. When all display fields on scan tool indicate "0", basic setting is complete. Press right arrow button to end procedure.

READ MEASURING VALUE BLOCK

Note. A/C control heads without an index letter in part number have 10 measuring value blocks, and A/C control heads with an index letter in part number have 11 measuring blocks. Each measuring block contains 4 measured values. When performing READ MEASURING VALUE BLOCK, function 08, control of A/C system is possible (compressor operates, air distribution control is possible, etc.). Readouts in display groups 02 through 05 show actual measured values (servo motor potentiometer resistances) learned during last basic setting. Position of air/temperature distribution flaps can be altered by manual control of control panel and corresponding flap positions can be determined by watching display values change. Measured values in display must correspond to specified values.

1. Check Diagnostic Trouble Code (DTC) memory. See «RETRIEVING & CLEARING DIAGNOSTIC TROUBLE CODES»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system__retrieving-clearing-diagnostic-trouble-codes) under SELF-DIAGNOSTICS. Repair A/C system malfunctions (if any). After checking DTC memory, keep engine operating and turn A/C system to AUTO mode. Operate fan at high speed for about one minute.
2. Ensure scan tool is in A/C HEATING ELECTRONICS function. With RAPID DATA TRANSFER displayed on scan tool, press "0" and "8" buttons to select READ MEASURING VALUE BLOCK function. Press "Q" button to confirm input.
3. With ENTER DISPLAY GROUP NUMBER displayed on scan tool, enter desired display group number. See «DISPLAY GROUP NUMBER IDENTIFICATION»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system) table. Press "Q" button to confirm input.
4. With READ MEASURING VALUE BLOCK X displayed on scan tool, check component function, measured value, or operating conditions using display field reference. See «DISPLAY GROUP NUMBER IDENTIFICATION»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system) table. To select a different display group number, press "C" button. Press right arrow button to end procedure.

DISPLAY GROUP NUMBER IDENTIFICATION

OUTPUT DIAGNOSTIC TEST MODE

Note. During output diagnostic test mode, vehicle must not be moved and engine speed must be less than 3000 RPM. The A/C-heater control system is switched off and all A/C-heater control panel displays are activated.

1. Start engine. Press AUTO button to switch on A/C compressor. Adjust airflow to center instrument panel outlets. Check Diagnostic Trouble Code (DTC) memory. See «RETRIEVING & CLEARING DIAGNOSTIC TROUBLE CODES»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system__retrieving-clearing-diagnostic-trouble-codes) under SELF-DIAGNOSTICS. Press PRINT button to turn on scan tool printer.
2. Ensure scan tool is in A/C HEATING ELECTRONICS function. With RAPID DATA TRANSFER displayed on scan tool, press "0" and "3" buttons to select OUTPUT DIAGNOSTIC TEST MODE function. Press "Q" button to confirm input.
3. Use right arrow button to advance through component checks. See «OUTPUT DIAGNOSTIC TEST MODE»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system) table. If FUNCTION UNKNOWN OR CANNOT BE CARRIED OUT AT THE MOMENT is displayed at start of test, press button and re-enter test. If FUNCTION UNKNOWN OR CANNOT BE CARRIED OUT AT THE MOMENT is still displayed, read measuring value block. See «READ MEASURING VALUE BLOCK»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system__read-measuring-value-block) .
4. Output diagnostic test mode can be ended by pressing "C" button. When test is complete, FUNCTION UNKNOWN OR CANNOT BE CARRIED OUT AT THE MOMENT will be displayed. After ending output diagnostic test mode, check DTC memory. See «RETRIEVING & CLEARING DIAGNOSTIC TROUBLE CODES»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system__retrieving-clearing-diagnostic-trouble-codes) under SELF-DIAGNOSTICS. Press right arrow button to end procedure.

OUTPUT DIAGNOSTIC TEST MODE

A/C COMPRESSOR SWITCH-OFF CONDITIONS (DISPLAY GROUP NO. 01)

TEMPERATURE REGULATOR FLAP MOTOR (DISPLAY GROUP NO. 02)

CENTRAL FLAP MOTOR (DISPLAY GROUP NO. 03)

FOOTWELL/DEFROSTER FLAP MOTOR (DISPLAY GROUP 04)

AIRFLOW FLAP MOTOR (DISPLAY GROUP 05)

AIR TEMPERATURE SENSORS & DISPLAY, & SUNLIGHT PHOTO SENSOR (DISPLAY GROUP 06)

MEASURED VALUE OF SENSORS FOR OUTLET TEMPERATURE & INTERIOR TEMPERATURE SENSOR (DISPLAY GROUP 07)

VOLTAGE AT FRESH AIR BLOWER & ILLUMINATION OF DISPLAY ELEMENTS (DISPLAY GROUP 08)

ENGINE SPEED & VEHICLE SPEED (DISPLAY GROUP 09)

ENGINE COOLANT TEMPERATURE SWITCH, A/C COMPRESSOR CUT-IN, A/C HIGH-PRESSURE SENSOR & CONVERTIBLE TOP ACTIVATION (DISPLAY GROUP 10)

LAST 4 COMPRESSOR CUT-OFF CONDITIONS (DISPLAY GROUP 11)

DTC 00000: NO DTC RECOGNIZED

System is operating properly.

DTC 00532: SUPPLY VOLTAGE TOO LOW

Note. If voltage at A/C-heater control panel connector drops to less than 9.5 volts, A/C compressor will switch off for a minimum of 25 seconds. A/C compressor will switch on again when voltage exceeds 10.8 volts.

Possible Causes

Voltage drops to less than 9.5 volts. Check for high resistance in wiring harness and all A/C system connections.

Corrective Actions

Check generator and voltage regulator. Repair high resistance in wiring harness or connections to all A/C system components. See WIRING DIAGRAMS .

DTC 00600: TEMPERATURE REGULATOR FLAP MOTOR POSITION SENSOR

Note. When fault exists at temperature regulator flap motor position sensor, flap motor can be set manually by turning temperature control lever to hot or cold selections.

Shorted or open circuit between temperature regulator flap motor position sensor and A/C-heater control panel. Interchanged wires between temperature regulator flap motor position sensor and A/C-heater control panel. Temperature flap not operating freely. Inoperative temperature regulator flap motor position sensor.

Repair shorted, open, or incorrect wiring between temperature regulator flap motor position sensor and A/C-heater control panel. Repair binding of temperature flap. Replace temperature flap motor.

DTC 00601: CENTRAL FLAP MOTOR POSITION SENSOR

Note. If travel limit is exceeded, fault will only be recognized during basic setting procedure.

Shorted or open circuit between central flap motor position sensor and A/C-heater control panel. Central flap not operating freely. Inoperative central flap motor position sensor.

Repair shorted, open or incorrectly routed wiring between central flap motor position sensor and A/C-heater control panel. Repair binding of central flap (both end stops must be reached). Replace central air flap motor.

DTC 00602: FOOTWELL/DEFROSTER MOTOR POSITION SENSOR

Note. If travel limit is exceeded, fault will only be recognized during basic setting procedure.

Shorted or open circuit between footwell/defroster flap motor position sensor and A/C-heater control panel. Footwell/defroster flap not operating freely. Inoperative footwell/defroster flap motor position sensor.

Repair shorted, open, or incorrectly routed wiring between footwell/defroster flap motor position sensor and A/C-heater control panel. Repair binding of footwell/defroster flap (both end stops must be reached). Replace footwell/defroster flap motor.

Shorted or open circuit between footwell/defroster flap motor and A/C-heater control panel. Footwell/defroster flap not operating freely. Inoperative footwell/defroster flap motor.

Repair shorted, open, or incorrectly routed wiring between footwell/defroster flap motor and A/C-heater control panel. See WIRING DIAGRAMS . Repair binding of footwell/defroster flap (both end stops must be reached). Check footwell/defroster flap motor operation.

DTC 00604: BACK PRESSURE FLAP MOTOR POSITION SENSOR

Note. If travel limit is exceeded, fault will only be recognized during basic setting procedure.

Shorted or open circuit between back pressure flap motor position sensor and A/C-heater control panel. Airflow flap not operating freely. Airflow flap motor not operating.

Repair shorted, open, or incorrectly routed wiring between back pressure flap motor position sensor and A/C-heater control panel. Repair binding of airflow flap (both end stops must be reached). Replace airflow flap motor.

Poor connections between vehicle speed sensor, instrument cluster, vehicle speed sensor related components (i.e., radio or cruise control module), and A/C-heater control panel. Unusable signal supplied by speedometer or instrument cluster. Disruption of signal by vehicle speed sensor related component.

Locate and repair poor connections between vehicle speed sensor, instrument cluster, vehicle speed sensor related components, and A/C-heater control panel. Check road speed signal between speedometer, instrument cluster, and vehicle speed sensor related components.

Shorted or open circuit between outside air temperature sensor and A/C-heater control panel. Faulty outside air temperature sensor.

Repair shorted or open circuit between outside air temperature sensor and A/C-heater control panel. See WIRING DIAGRAMS . Test outside air temperature sensor. See TEMPERATURE SENSORS under COMPONENT TESTS.

Shorted or open circuit between instrument panel interior temperature sensor and A/C-heater control panel. Inoperative instrument panel interior temperature sensor.

Instrument panel interior temperature sensor is incorporated in A/C-heater control panel with one display. Instrument panel interior temperature sensor cannot be checked or replaced individually. If sensor is malfunctioning, replace A/C-heater control panel.

Shorted or open circuit between fresh air intake duct temperature sensor and A/C-heater control panel. Inoperative fresh air intake duct temperature sensor.

Repair shorted or open circuit between fresh air intake duct temperature sensor and A/C-heater control panel. Test fresh air intake duct temperature sensor. See TEMPERATURE SENSORS under COMPONENT TESTS.

Open circuit between coolant fan control module and A/C-heater control panel. Open circuit between A/C high-pressure sensor and coolant fan control module. Open circuit in voltage or ground to A/C high-pressure sensor. Short circuit to voltage or ground between A/C high-pressure sensor, coolant fan control module or ECM. Cooling fan malfunction. Cooling fan second stage malfunction caused by cooling fan control module. Condenser or radiator dirty. Excess or low refrigerant system pressure.

Repair shorted or open circuit in wiring. Check cooling fan first stage operation. See OUTPUT DIAGNOSTIC TEST MODE under SELF-DIAGNOSTICS. Check cooling fan operation, by-passing A/C high-pressure sensor if necessary. See A/C HIGH-PRESSURE SENSOR under COMPONENT TESTS. Clean condenser or radiator. Check refrigerant system pressure.

Possible Cause

Open circuit in power supply to interior temperature sensor fan or in wiring harness between sensor fan and A/C-heater control panel. Inoperative interior temperature sensor fan.

Repair shorted or open power supply circuits. Interior temperature sensor fan is incorporated in A/C-heater control panel with one display. Instrument panel interior temperature sensor fan cannot be checked or replaced individually. If sensor is malfunctioning, replace A/C-heater control panel.

Shorted or open circuit between sunlight photo sensor and A/C-heater control panel. Inoperative sunlight photo sensor.

Repair shorted, open, or incorrectly routed wiring between sunlight photo sensor and A/C-heater control panel. See WIRING DIAGRAMS . Test sunlight photo sensor. See READ MEASURING VALUE BLOCK under SELF-DIAGNOSTICS. Replace sunlight photo sensor if necessary.

Coding of A/C-heater control panel not performed according to specification or incorrect code was entered.

Code A/C-heater control panel according to specifications. See A/C-HEATER CONTROL PANEL CODING under PROGRAMMING.

A malfunction occurred during basic setting function or ignition was turned off and A/C-heater control panel could not complete basic setting function. Basic setting was not performed after replacement of control panel. Basic setting was performed on a non-coded or incorrectly coded A/C-heater control panel.

Check A/C-heater control panel coding. Perform basic setting of A/C-heater control panel. See A/C-HEATER CONTROL PANEL CODING under PROGRAMMING.

DTC 01206: SIGNAL FOR TIME SPAN IGNITION OFF (INCORRECT SIGNAL)

Note. If A/C-heater control panel is unable to determine duration of time when ignition is off (standing time), DTC 01206 is loaded into memory. The A/C-heater control panel will default to a standing time greater than 4 hours. Actual measured values of outside temperature sensor are then used as outside and engine temperature inputs for A/C system control. When heating mode is selected under these conditions, fresh air blower has a delayed start (even when actual standing time is less than 4 hours and engine is warm). Outside air temperature display may also indicate incorrect outside temperature values.

Shorted or open circuit between instrument cluster and A/C-heater control panel. Instrument cluster malfunction.

Repair shorted or open circuit in wiring. Check signal from instrument cluster. See READ MEASURING VALUE BLOCK under SELF-DIAGNOSTICS.

Shorted or open circuits between temperature regulator flap motor and A/C-heater control panel. Sticking temperature flap. Faulty temperature regulator flap motor.

Repair shorted, open, or incorrectly routed wiring between temperature regulator flap motor and A/C-heater control panel. See WIRING DIAGRAMS . Check for free operation of temperature flap. Test temperature regulator flap motor. See OUTPUT DIAGNOSTIC TEST MODE under SELF-DIAGNOSTICS.

Shorted or open circuits between central air flap motor and A/C-heater control panel. Sticking central flap. Faulty central air flap motor.

Repair shorted, open, or incorrectly routed wiring between central air flap motor and A/C-heater control panel. Check for free operation of central flap. Test central air flap motor. See OUTPUT DIAGNOSTIC TEST MODE under SELF-DIAGNOSTICS.

Shorted or open circuit between fresh air blower, fresh air blower control module, and A/C-heater control panel. Open power or ground circuit to fresh air blower control module. Faulty fresh air blower control module. Faulty fresh air blower.

Repair shorted or open circuit between fresh air blower, fresh air blower control module and A/C-heater control panel. Repair open power or ground circuit to fresh air blower control module. Test fresh air blower control module. See FRESH AIR BLOWER & FRESH AIR BLOWER CONTROL MODULE under COMPONENT TESTS. Replace fresh air blower.

Shorted or open circuits between airflow flap motor and A/C-heater control panel. Interchanged wires between airflow flap motor and A/C-heater control panel. Air flap binding/sticking. Faulty airflow flap motor.

Repair shorted, open, or incorrectly routed wiring between airflow flap motor and A/C-heater control panel. Check for free operation of airflow flap. Test airflow flap motor. See OUTPUT DIAGNOSTIC TEST MODE under SELF-DIAGNOSTICS.

Short or open circuit in wiring or connectors. Malfunctioning sensor.

Repair shorted, open, or incorrect wiring. See WIRING DIAGRAMS . Replace defective outlet temperature sensor.

Short or open circuit in wiring or connectors. Malfunctioning sensor.

Repair shorted, open, or incorrect wiring. Replace defective floor outlet temperature sensor.

Short or open circuit in wiring or connectors, contact resistance or loose connection. Malfunctioning A/C-heater control panel.

Repair shorted, open, or incorrect wiring to A/C control panel. See WIRING DIAGRAMS . Replace A/C-heater control panel as necessary.

SYSTEM TESTS

A/C SYSTEM PERFORMANCE

1. Check for any Diagnostic Trouble Codes (DTCs) which may be present, and repair as necessary. See «RETRIEVING & CLEARING DIAGNOSTIC TROUBLE CODES»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system__retrieving-clearing-diagnostic-trouble-codes) under SELF-DIAGNOSTICS. Perform «BASIC SETTING»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system__basic-setting) . Perform «A/C-HEATER CONTROL PANEL CODING»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system__ac-heater-control-panel-coding) under PROGRAMMING.
2. Park vehicle out of direct sunlight. Ensure condenser and radiator are free of obstructions. Close engine hood. Ensure compressor drive belt and generator are in good condition. Ensure engine is at normal operating temperature. Close doors and windows. Record ambient temperature.
3. Start engine and operate it at 2000 RPM. Turn A/C system on and press recirculation button on. Set A/C-heater control panel to maximum cold position (AUTO mode and LO temperature selection).
4. Open all instrument panel air outlets. Operate air blower at maximum speed. Set air distribution so that air flows out of instrument panel vents.
5. Check outlet air temperature at center instrument panel vent after A/C system has operated for 5 minutes. See «A/C SYSTEM PERFORMANCE SPECIFICATIONS»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system) table.

A/C SYSTEM PERFORMANCE SPECIFICATIONS

Note. Test Box (VAG 1598) must not be connected to A/C-heater control panel connector when using Scan Tool (VAG 1551).

Test Equipment Hook-Up

1. Ensure battery voltage is okay. Ensure engine and transmission grounds are okay. Ensure fuses are okay.
2. Turn ignition off. Remove A/C-heater control panel, and disconnect electrical connectors. (Scheme 2) While performing tests, DO NOT connect adapter harnesses to A/C-heater control panel, or A/C-heater control panel will be damaged.
3. Connect Adapter Cable (VAG 1598/11 or 12) to appropriate A/C-heater control panel harness connector. For Adapter Cable (VAG 1598/12), terminals are identical to A/C-heater control panel terminals. For Adapter Cable (VAG 1598/11), adapter cable terminal numbers and A/C-heater control panel wiring harness terminal numbers are not the same. Connector "A" terminals No. 1-12 are identified as terminals No. 41-52 on adapter cable. Connector "B" terminals No. 1-20 are identified as terminals No. 21-40. Connector "C" and "D" terminals No. 1-16 are identified as terminals No. 1-16.

Note. When Adapter Cable (VAG 1598/11) is connected, no ground connection exists. Use external ground source or second adapter cable during electrical testing. When Adapter Cable (VAG 1598/12) is connected, ground exists at terminals No. 14 and 15.

Scheme 2

Test Procedure

Note. Ground connection for test procedure is available at connector "D" terminal No. 15.

1. Using Adapter Cable (VAG 1598/12) and DVOM in 20-volt range, check voltage between adapter cable terminals No. 9 and 15 with ignition on. Ensure battery voltage exists. If battery voltage does not exist, check wire between fuse block and A/C-heater control panel. Also check wires between A/C-heater control panel and ground. See «WIRING DIAGRAMS»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system) .
2. Using DVOM, check voltage between adapter cable terminal No. 46 and ground with ignition on and parking lights turned on. Battery voltage should be present. If battery voltage is not present, check wire between fuse block and A/C-heater control panel.
3. Using DVOM, check voltage between adapter cable terminal No. 46 and ground with ignition on and parking lights turned off. Zero volts should be present. If zero volts are not present, check for short to voltage in wire between fuse block and A/C-heater control panel. See «WIRING DIAGRAMS»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system) .
4. Using DVOM, check voltage between adapter cable terminal No. 7 and ground with ignition on and side lights on. Voltage should be 0-12 volts depending on illumination rheostat setting (instrument panel illumination dimmer switch). If voltage is not as specified, repair open or short in wire.
5. Using DVOM, check voltage between adapter cable terminal No. 7 and ground with ignition on and side lights off. Voltage should be zero volts. If voltage is not as specified, repair short circuit to voltage in wire. See «WIRING DIAGRAMS»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system) . NOTE: Voltage at terminal No. 45 is generated as a square-wave signal by instrument cluster. Brightness of display is determined by period of activation. DVOM will show mean period of activation.
6. Using DVOM, check voltage between adapter cable terminal No. 45 and ground with ignition on and parking lights turned on. Voltage should be 0-12 volts depending on illumination rheostat setting (instrument panel illumination dimmer switch). If voltage is not as specified, repair open or short in wire.
7. Using DVOM, check voltage between adapter cable terminals No. 45 and ground with ignition on and parking lights turned off. Voltage should be 0-12 volts depending on illumination rheostat setting (instrument panel illumination dimmer switch). If voltage is not as specified, repair open or short in wire. See «WIRING DIAGRAMS»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system) .
8. Connect Adapter Cable (VAG 1598/11) to A/C-heater control panel. Connect LED Voltage Tester (VAG 1527B) between ground and adapter cable terminal No. 33. Turn ignition on. LED should illuminate. If LED does not illuminate, repair open or short in wire.
9. With Adapter Cable (VAG 1598/11) and LED Voltage Tester (VAG 1527B) still connected, start engine and allow to idle. LED should flicker briefly (time signal) and then illuminate. If LED does not flicker, check signal from instrument cluster. Repair as necessary. See «WIRING DIAGRAMS»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system) .

A/C HIGH-PRESSURE SENSOR, A/C COMPRESSOR SIGNAL, ENGINE TEMPERATURE SIGNAL & CONVERTIBLE TOP SIGNAL

1. Using DVOM to measure voltage, connect test leads between adapter cable terminal No. 2 and ground. If battery voltage is not present, check for open circuit or high resistance in A/C high-pressure sensor circuit. Check A/C high-pressure sensor. See «A/C HIGH-PRESSURE SENSOR»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system) under COMPONENT TESTS. Repair or replace as necessary.
2. Connect LED voltage tester between ground and adapter cable terminal No. 51. Start engine and allow to idle. LED should illuminate. If LED does not illuminate, check for short to ground between A/C compressor and A/C-heater control panel. Check for A/C compressor switch-off conditions caused by instrument cluster. See «A/C COMPRESSOR SWITCH-OFF CONDITIONS (DISPLAY GROUP NO. 01)»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system) table under SELF-DIAGNOSTICS. Repair or replace as necessary.
3. Connect LED Voltage Tester (VAG 1527B) between Adapter Cable (VAG 1598/11) terminals No. 12 and 14. Start engine and ensure A/C compressor is OFF. LED in ECON (economy) switch should illuminate. If LED does not illuminate, check for open or short circuit in wiring between A/C compressor and A/C-heater control panel. Repair or replace as necessary.
4. Ensure LED voltage tester is still connected between adapter cable terminals No. 12 and 14. Start engine and ensure A/C compressor is ON. LED should illuminate slightly dimmer than in previous step. If LED does not illuminate as specified, check for A/C compressor switch-off conditions caused by ECM or TCM. See «A/C COMPRESSOR SWITCH-OFF CONDITIONS (DISPLAY GROUP NO. 01)»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system) table under SELF-DIAGNOSTICS. Check for short to ground in wiring between A/C compressor and A/C-heater control panel. Repair or replace as necessary.
5. Set DVOM to 200-milliamp scale. Connect test leads between ground and adapter cable terminal No. 12. Start engine and allow to idle. With A/C compressor off, less than 5 milliamps should be present. If more than 5 milliamps are present, repair short to voltage.
6. With A/C compressor on, less than 50 milliamps should be present (compressor not engaged). If greater than 50 milliamps are present, replace A/C-heater control panel.
7. Remove test leads from adapter cable. Ensure A/C compressor engages. If A/C compressor does not engage, check for A/C compressor switch-off conditions caused by ECM or TCM. See «A/C COMPRESSOR SWITCH-OFF CONDITIONS (DISPLAY GROUP NO. 01)»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system) table under SELF-DIAGNOSTICS. Check for short to ground in wiring between A/C compressor and A/C-heater control panel. Repair or replace as necessary. NOTE: For Coupe, go to next step. For Roadster, go to step 9 .
8. Connect LED Voltage Tester (VAG 1527B) between Adapter Cable (VAG 1598/11) terminals No. 5 and 14. Turn ignition on. LED should not illuminate. If LED does illuminate, check for short circuit to ground in wiring between convertible top and A/C-heater control panel. Repair as necessary.
9. Connect LED Voltage Tester (VAG 1527B) between Adapter Cable (VAG 1598/11) terminals No. 5 and 14. Turn ignition on. With convertible top closed, LED should not illuminate. If LED does illuminate, check for short circuit to ground in wiring between convertible top and A/C-heater control panel. Check convertible top control unit. Repair as necessary.
10. With convertible top open, LED should illuminate. If LED does not illuminate, check for open circuit in wiring between convertible top and A/C-heater control panel. Check convertible top control unit. Repair as necessary.

A/C CLUTCH RELAY & COOLANT FAN LOW SPEED OPERATION

1. Using Adapter Cable (VAG 1598/11) and DVOM in 20-amp range, check amperage between adapter cable terminals No. 14 and 42. Start engine and allow to idle. Amperage reading should be less than one amp, with A/C compressor engaged and operating. If conditions are not as specified, check for short or open circuits between A/C clutch, A/C clutch relay, and A/C-heater control panel. Check A/C high-pressure sensor. See «A/C HIGH-PRESSURE SENSOR»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system) . Check operation of A/C compressor clutch and A/C clutch relay. Repair or replace as necessary.
2. Start engine and allow to idle. Check amperage between adapter cable terminals No. 14 and 42. Amperage should be less than one amp, with cooling fan operating in low speed. If conditions are not as specified, check for short or open circuits between cooling fan control relay and A/C-heater control panel. Check cooling fan. Repair or replace as necessary.

Start engine and allow to idle. Turn A/C on, using AUTO operating mode on A/C control panel. Connect A/C gauge set and monitor A/C system pressures. Using oscilloscope set to 2 volt divisions (DC) and 5 milliseconds per division, backprobe between A/C high-pressure sensor harness connector terminal No. 2 and ground. (Scheme 3) Depending on system pressure at A/C high-pressure sensor, a varying signal pattern should be indicated on oscilloscope. When system pressure rises, signal's pulse width increases. When system pressure drops, signal's pulse width decreases. If operation is not as specified, replace high pressure sensor.

Scheme 3

TEMPERATURE SENSORS

1. Using Adapter Cable (VAG 1598/12) and DVOM in 20 k/ohm range, check resistance between adapter cable terminals No. 48 and 49. Measure temperature at mounting location of outside air temperature sensor. See «FRESH AIR INTAKE DUCT TEMPERATURE SENSOR & OUTSIDE AIR TEMPERATURE SENSOR RESISTANCE»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system) table. If resistance is not as specified, check for short, open, or high resistance in wire between A/C-heater control panel and outside air temperature sensor. Also check wire between sensor and ground. See «WIRING DIAGRAMS»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system) . Check outside air temperature sensor. Repair or replace as necessary.
2. Check resistance between adapter cable terminals No. 47 and 49. Measure temperature at mounting location of fresh air intake duct temperature sensor. See «FRESH AIR INTAKE DUCT TEMPERATURE SENSOR & OUTSIDE AIR TEMPERATURE SENSOR RESISTANCE»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system) table. If resistance is not as specified, check for short, open, or high resistance in wire between A/C-heater control panel and fresh air intake duct temperature sensor. Also check wire between sensor and ground. Check fresh air intake duct temperature sensor. Repair or replace as necessary.
3. Check resistance between adapter cable terminals No. 25 and 49. Measure temperature at mounting location of floor outlet temperature sensor. See «FLOOR OUTLET TEMPERATURE SENSOR RESISTANCE»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system) table. If resistance is not as specified, check for short, open, or high resistance in wire between A/C-heater control panel and center outlet temperature sensor. Also check wire between sensor and ground. See «WIRING DIAGRAMS»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system) . Check floor outlet temperature sensor. Repair or replace as necessary.

FRESH AIR INTAKE DUCT TEMPERATURE SENSOR & OUTSIDE AIR TEMPERATURE SENSOR RESISTANCE

FLOOR OUTLET TEMPERATURE SENSOR

FRESH AIR BLOWER & FRESH AIR BLOWER CONTROL MODULE

1. Using Adapter Cable (VAG 1598/11) and DVOM in 20-volt range, check voltage between adapter cable terminal No. 16 and ground with ignition on. Voltage should be less than 5 volts and blower should not operate. If conditions are not as specified, check for short to battery voltage in wire between fresh air blower control module and A/C-heater control panel. See «WIRING DIAGRAMS»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system) . Check fresh air blower control module. Repair or replace as necessary.
2. Check voltage between adapter cable terminal No. 14 and ground with ignition on. Battery voltage should exist. If battery voltage does not exist, check for open circuit in wire between A/C-heater control panel and fresh air blower. Repair as necessary.
3. Check voltage between adapter cable terminal No. 11 and ground with ignition on. Battery voltage should exist. If battery voltage does not exist, check for open circuit in wire between fresh air blower control module and fresh air blower. See «WIRING DIAGRAMS»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system) . Repair as necessary.
4. Connect LED Voltage Tester (VAG 1527B) between Adapter Cable (VAG 1598/11) terminals No. 14 and 16. Turn ignition on. Ensure LED illuminates and fresh air blower operates. If conditions are not as specified, check for open circuit in wiring between fresh air blower control module and A/C-heater control panel. Ensure fresh air blower operates freely. Repair or replace as necessary.

AIR/TEMPERATURE DISTRIBUTION FLAP MOTORS & SENSORS

Note. Potentiometer resistance (3600-5700 ohms between flap motor terminals No. 3 and 4) can only be measured directly at flap motor. Measure with flap motor installed. If any potentiometer-related DTC is set, test all potentiometers.

1. Ensure ignition is off. Using Adapter Cable (VAG 1598/12) and DVOM in 20 k/ohm range, check resistance between adapter cable terminal No. 52 and indicated terminals. See «ADAPTER CABLE TERMINAL IDENTIFICATION»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system) table. Resistance should be greater than 100 ohms and less than 5700 ohms, depending on position of flap motor. If resistance is not as specified, check for short, open, or high resistance in circuits between inoperative flap motor, A/C-heater control panel, and ground. Check inoperative flap motor. Repair or replace as necessary.
2. Check resistance between adapter cable terminal No. 8 and indicated terminals. See «ADAPTER CABLE TERMINAL IDENTIFICATION»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system) table. Resistance should be greater than 100 ohms and less than 5700 ohms, depending on position of flap motor. If resistance is not as specified, check for short, open, or high resistance in circuits between inoperative flap motor, A/C-heater control panel, and ground. Check inoperative flap motor. Repair or replace as necessary. ADAPTER CABLE TERMINAL IDENTIFICATION Application Adapter Cable (VAG 1598/12) Terminal No. Temperature Regulator Flap Motor 28 Central Air Flap Motor 29 Airflow Flap Motor 37 Footwell/Defroster Flap Motor 30
3. Using Adapter Cable (VAG 1598/12) and DVOM in 200-ohm range, check resistance between adapter cable terminals No. 2 and 10. Ensure resistance is 20-100 ohms. If resistance is not as specified, check for short, open, or high resistance in circuits between temperature regulator flap motor, A/C-heater control panel, and ground. Check temperature regulator flap motor. Repair or replace as necessary.
4. Check resistance between adapter cable terminals No. 4 and 12. Ensure resistance is 20-100 ohms. If resistance is not as specified, check for short, open, or high resistance in circuits between central flap motor, A/C-heater control panel, and ground. Check central flap motor. Repair or replace as necessary.
5. Check resistance between adapter cable terminals No. 5 and 13. Ensure resistance is 20-100 ohms. If resistance is not as specified, check for short, open, or high resistance in circuits between airflow flap motor, A/C-heater control panel, and ground. Check airflow flap motor. Repair or replace as necessary.
6. Check resistance between adapter cable terminals No. 3 and 11. Ensure resistance is 20-100 ohms. If resistance is not as specified, check for short, open, or high resistance in circuits between footwell/defroster flap motor, A/C-heater control panel, and ground. Check footwell/defroster flap motor. Repair or replace as necessary.

REMOVAL & INSTALLATION

1. Discharge A/C system, using approved refrigerant recovery/recycling equipment. Mark direction of drive belt. Loosen drive belt tensioner and remove drive belt. If vehicle is equipped with two intercoolers, remove connecting pipe between them. Remove bolts and A/C compressor. (Scheme 4) Remove and plug refrigerant lines from A/C compressor. Discard "O" rings.
2. To install, reverse removal procedure. Lubricate "O" rings with clean refrigerant oil. Tighten connections to specification. See «TORQUE SPECIFICATIONS»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system__torque-specifications). Evacuate and charge A/C system.

Scheme 4

A/C-HEATER ASSEMBLY

Removal

1. Discharge A/C system, using approved refrigerant recovery/recycling equipment. Turn ignition on and press recirculated air button on A/C control panel. Wait until air flow flap moves fully to recirculated air position. Turn ignition off.
2. Remove A/C air filter. Move power seats to rearmost position. Obtain radio anti-theft protection code form owner. Disable air bag system. See AIR BAG SYSTEM SAFETY article in GENERAL SERVICING. Remove coolant expansion tank cap slowly to release cooling system pressure.
3. Clamp coolant hoses, and disconnect hoses from heater core. Place container under heater core connections, and apply compressed air through inlet hole to blow coolant out of heater core. Remove bolts and refrigerant lines from evaporator. Plug evaporator connections to prevent contamination. Remove boot from evaporator.
4. Fold back pre-punched flaps on insulation mat and remove hex nuts and washers at firewall. Remove glove box assembly. Remove bolts from driver's side storage compartment assembly and remove storage compartment. Remove center console. Remove footwell vent and air duct leading to defroster vent.
5. Remove passenger's air bag module and instrument panel cross member left-hand bracket. Disconnect ground connection at bottom of right "A" pillar. Cover all exposed connectors and air ducts. Using 7 mm drill bit, drill out 2 welds in instrument panel support brace. Saw through support at specified point. (Scheme 5) Bend and move upper portion of brace downward along perforated holes. Disconnect electrical connectors and remove Heating Ventilation Air Conditioning (HVAC) unit.

Scheme 5

Installation

1. To install, reverse removal procedure. Replace all damaged A/C-heater seals and cable tie wraps. Replace inlet/outlet "O" rings. Ensure refrigerant lines fit into evaporator without binding. Bend and move upper portion of brace back into position and install bolts.
2. Ensure evaporator drain valve is correctly installed. Evacuate and charge A/C system. Tighten nuts and bolts to specification. See «TORQUE SPECIFICATIONS»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system__torque-specifications) .

Note. Check for codes before removing A/C-heater control panel. See RETRIEVING & CLEARING DIAGNOSTIC TROUBLE CODES under SELF-DIAGNOSTICS. After A/C-heater control panel is replaced, check coding and perform basic setting. See BASIC SETTING under SELF-DIAGNOSTICS. Check for codes, and repair as necessary.

Obtain radio anti-theft protection code. Disconnect negative battery cable. Remove radio. Remove 2 grips from center console. Remove screws and center instrument panel trim. Remove screws and A/C-heater control panel. Push back connector locks, and disconnect electrical connectors. To install, reverse removal procedure. Tighten screws to specification. See TORQUE SPECIFICATIONS .

AIR/TEMPERATURE DISTRIBUTION FLAP MOTORS

Note. After installing a flap motor, ensure motor lever is correctly positioned. Check for codes. See RETRIEVING & CLEARING DIAGNOSTIC TROUBLE CODES under SELF-DIAGNOSTICS. Test appropriate flap motor. See OUTPUT DIAGNOSTIC TEST MODE under SELF-DIAGNOSTICS. See AIR/TEMPERATURE DISTRIBUTION FLAP MOTORS & SENSORS under COMPONENT TESTS.

Removal & Installation (Airflow Flap Motor)

1. Disable air bag system. See AIR BAG SYSTEM SAFETY article in GENERAL SERVICING. Remove glove box. Disconnect electrical connector from motor. (Scheme 7) Remove bolts attaching motor to A/C-heater assembly. Rotate airflow flap motor downward and pull out of shaft for fresh/recirculated air flap.
2. To install, reverse removal procedure. Before installing motor, connect motor to airflow flap motor harness connector. Turn ignition on. Press recirculated air button on A/C-heater control panel to centralize actuating arm in order to facilitate installation. Ensure that metal lever moves airflow flap and is inserted into closed guide groove. Ensure that plastic lever moves the fresh/recirculated air flap and only assumes an open guide groove position when in recirculated air mode.

Removal & Installation (Central & Temperature Regulator Flap Motors)

Remove footwell duct/vent. (Scheme 6) Remove 3 screws from flap motor. Disconnect electrical connector from motor. Disengage actuating arm and remove flap motor. (Scheme 7) To install, reverse removal procedure.

Scheme 6

Scheme 7

Removal & Installation (Footwell/Defroster Flap Motor)

Remove driver's storage compartment. Remove footwell/defroster flap motor. (Scheme 7) To install, reverse removal procedure.

Remove driver's storage compartment. Disconnect electrical connector from sensor. (Scheme 7) Turn sensor 90 degrees and remove. To install, reverse removal procedure.

Remove right cowl air plenum cover. Remove water guide. Remove dust/pollen filter. To install, reverse removal procedure.

Discharge refrigerant circuit. Unbolt and remove refrigerant pipes from expansion valve. Remove expansion valve and threaded plate. To install, reverse removal procedure.

1. Remove A/C-heater assembly. See «A/C-HEATER ASSEMBLY»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system__ac-heater-assembly). Remove heater core. See «HEATER CORE»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system). Remove fresh air blower. (Scheme 8)
2. Remove airflow flap motor. (Scheme 7) Remove top part of evaporator housing and gasket. Remove evaporator.

Scheme 8

1. To install, reverse removal procedure. Ensure foam gasket around evaporator core has a gap along bottom (to allow condensation drainage). Use foam gasket to seal refrigerant lines at air distribution housing halves.
2. Check for codes. See «RETRIEVING & CLEARING DIAGNOSTIC TROUBLE CODES»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system__retrieving-clearing-diagnostic-trouble-codes) under SELF-DIAGNOSTICS. Test airflow flap motor. See «OUTPUT DIAGNOSTIC TEST MODE»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system__output-diagnostic-test-mode) under SELF-DIAGNOSTICS. See «AIR/TEMPERATURE DISTRIBUTION FLAP MOTORS & SENSORS»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system__airtemperature-distribution-flap-motors-sensors) under COMPONENT TESTS.

Disable air bag system. See AIR BAG SYSTEM SAFETY article in GENERAL SERVICING. Remove glove box and glove box mounting. Remove screw clip for foam covering and move foam aside. Remove 2 screws from lower blower cover. (Scheme 7) Disconnect electrical connector from fresh air blower. Pull blower downward out of housing. To install, reverse removal procedure.

Remove glove box and glove box mounting. (Scheme 7) Disconnect electrical connector from fresh air blower control module. Remove retaining screw and fresh air blower control module. To install, reverse removal procedure.

Disable air bag system. See AIR BAG SYSTEM SAFETY article in GENERAL SERVICING. Remove glove box and A/C air filter. Locate fresh air intake duct temperature sensor behind fresh air blower motor. Reach in between A/C-heater assembly and bulkhead and turn sensor 90 degrees clockwise. To install, reverse removal procedure. After sensor installation, check for codes. See RETRIEVING & CLEARING DIAGNOSTIC TROUBLE CODES under SELF-DIAGNOSTICS.

Remove A/C-heater assembly and instrument panel. See A/C-HEATER ASSEMBLY . Remove heater core retaining screws. Press catches on sides of heater core, and remove heater core from housing. To install, reverse removal procedure.

1. Discharge A/C system, using approved refrigerant recovery/recycling equipment. Remove bolt from lower receiver-drier refrigerant line. Unbolt bracket nut. Remove bolt from upper refrigerant line. Pull receiver-drier out of bottom of bracket.
2. To install, reverse removal procedure. Tighten refrigerant lines to specification. See «TORQUE SPECIFICATIONS»(/audi/tt/8n-1998-2003/remont/automatic-hvac-system/#automatic-ac-heater-system__torque-specifications) . Align spring with mounting hole on bracket and mark on refrigerant hose.

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

See also:
• BASIC SETTING
• SCAN TOOL DIAGNOSTIC FUNCTIONS
• OUTPUT DIAGNOSTIC TEST MODE
• A/C-HEATER CONTROL PANEL CODING
• READ MEASURING VALUE BLOCK
• 00000
• 00532
• 00600
• 00601
• 00602
• 00604
• 01206
• RETRIEVING & CLEARING DIAGNOSTIC TROUBLE CODES
• A/C HIGH-PRESSURE SENSOR, A/C COMPRESSOR SIGNAL, ENGINE TEMP. SIGNAL & INTERIOR TEMP. SENSOR FAN
• A/C SYSTEM PERFORMANCE
• TEMPERATURE SENSORS
• FRESH AIR BLOWER & FRESH AIR BLOWER CONTROL MODULE
• TORQUE SPECIFICATIONS
• AIR/TEMPERATURE DISTRIBUTION FLAP MOTORS & SENSORS
• A/C-HEATER ASSEMBLY