Generators & Regulators Audi TT 8N

DESCRIPTION

Bosch alternators are conventional 3-phase, self-rectifying type alternators. Bosch voltage regulators are transistorized and integral with alternator. Manufacturer recommends replacing generator as an assembly.

BELT TENSION

Serpentine belt tension is automatically adjusted by tensioner.

DRIVE BELT ROUTING

Note. Serpentine belt is self-adjusting. For drive belt routing (Scheme 1)

Scheme 1

Scheme 2

PRELIMINARY INSPECTION

Verify customer complaint by operating system. Visually inspect for obvious signs of mechanical and electrical damage. Check generator belt tension and condition. Ensure that battery voltage is within specifications. Following manufacturers instructions for load tester, load test battery. Inspect for blown fuses and damaged relays. For fuse and/or relay identification, see WIRING DIAGRAMS .

Verify ground connection integrity between engine, body, battery and generator. Check for damaged wiring harnesses and/or switches. Check for a broken or partially broken wire inside insulation, which could cause system malfunction but prove good in a continuity/voltage check with system disconnected. Ensure any aftermarket electronic equipment is properly installed. If fault is found, repair as necessary. If no fault is found, check for conditions that might cause an intermittent situation.

LOAD TEST

Note. Manufacturer recommends performing electrolyte specific gravity test, in order to determine battery overall condition. For specific gravity values, see SPECIFIC GRAVITY SPECIFICATIONS table.

Note. It is not necessary to remove battery from vehicle, or disconnect battery terminals.

Connect tester cable clamps to battery terminal. Ensure clamps have a good contact with battery terminals. Connect battery tester according to tool manufacturer's instructions. Load test battery at approximately one-half cold-cranking amperage rating for 15 seconds while observing battery voltage. If voltage reading is 9.0 volts or more, battery is okay. If voltage reading is less than 9.0 volts, charge battery and retest. If loaded battery voltage is still less than 9.0 volts after charging battery, replace battery.

SPECIFIC GRAVITY SPECIFICATIONS

NO LOAD TEST

Note. If no load voltage is to be measured with battery installed in vehicle, first disconnect ground strap.

Note. Vehicle must not be started or driven with tested battery for at least 2 hours before taking measurements. During this time, DO NOT allow load or additional charge to be applied to battery.

With battery installed and ignition switched off, check voltage between battery terminals with voltmeter. If no load voltage is 12.5 volts, or higher, battery is okay. If no load voltage is lower than 12.5, recharge battery, and repeat procedure. If battery voltage is still less than 12.5 after charging battery, replace battery.

BRUSHES

Remove generator. See GENERATOR under REMOVAL & INSTALLATION. Remove voltage regulator from back of generator. See VOLTAGE REGULATOR under REMOVAL & INSTALLATION. Brushes are integrated with voltage regulator. Brushes wear limit is 5 mm.

REMOVAL & INSTALLATION

Air Bag

ECM

If connector is disconnected from ECM or battery is disconnected, all adaptation values in control module are erased. To achieve optimal anti-theft protection for vehicle, an anti-theft immobilizer was installed. Anti-theft immobilizer is a system for enabling/locking Engine Control Module (ECM) through the W-wire.

This system cannot be circumvented, it is necessary to perform adaptation of anti-theft immobilizer using VAS 5052 in On Board Diagnostic function. The great availability of equipment options makes adaptation of ECM necessary (e.g. cruise control system). This "writing" function is not possible with a generic scan tool, therefore it is necessary to use VAS 5052 in On Board Diagnostic function for this purpose. DTC memory content will remain intact however. If engine is started after this, a rough, uneven idle can result. In this case, ECM readiness code must be regenerated.

ECM Readiness Code

While limited diagnostic information is available, vehicle manufacturer does not support diagnostic information using aftermarket scan tools. To properly diagnose vehicle, it is recommended to use VAS 5051 scan tool with VAS 5051/1 adapter cable or VAG 1551 scan tool with 1551/3A adapter cable and VAG 1598/31 test box.

Readiness code must be generated when Engine Control Module (ECM) memory is cleared, battery voltage is disconnected or ECM is disconnected. To generate readiness code, vehicle must be stationary, transmission in Park or Neutral, all electrical consumers off, A/C switched off and coolant temperature at least 176°F (80°C). If possible, it is best to warm-up vehicle by test driving. Connect scan tool to DLC. DLC is located behind cover under left side of steering column.

Power Windows

After connecting battery, completely open and close all power windows.

Radio & Clock

Vehicles are equipped with an anti-theft stereo system that requires a code to activate. Record stereo code BEFORE disconnecting negative battery cable. Disconnect negative battery cable. Turn ignition to ON position. Reconnect negative battery cable. Enter code into stereo and reset clock.

Removal & Installation (1.8L - ATC & AWP)

1. Disconnect harness connector at throttle valve control module (J388), and charge pressure sender (G31). Disconnect air hose (1) at throttle valve control module. (Scheme 3) Disconnect vacuum hose (2) connecting charcoal filter-to-throttle valve control module at throttle valve control module.
2. Unscrew nut (2), and pull out activated charcoal filter (3) from top. (Scheme 4) Place activated charcoal filter on engine cover panel.
3. Using chalk or felt pen, mark serpentine belt direction of rotation. To loosen belt, turn tensioning element in direction of arrow. (Scheme 5)
4. On vehicles without headlight washer system, secure tensioner with special tool (3090). (Scheme 6) On all other vehicles, tensioner may be secured with a mandrel (4.5 mm diameter and 55 mm long). On all vehicles, remove belt.
5. Remove nut (1) from terminal 30/B+ connection. (Scheme 7) Disconnect electrical connector (2). Remove harness retainer (3). Remove M8 hex bolts connecting generator to bracket. Lift generator out from engine compartment.
6. To install, reverse removal. Ensure belt is correctly routed and properly seated. Tighten all bolts to specification. See «TORQUE SPECIFICATIONS»(/audi/tt/8n-1998-2003/remont/charging-system/#generators-regulators__torque-specifications).

Scheme 3

Scheme 4

Scheme 5

Scheme 6

Scheme 7

Removal & Installation (1.8L - AMU & BEA)

1. Remove right engine compartment trim pieces (arrows). (Scheme 8) Push clamp pin through expanding clip, and remove clip from trim. Release securing clip (3) to release trim (4). (Scheme 9)
2. Unscrew nut (2), and pull out activated charcoal filter (3) from top. (Scheme 4) Place activated charcoal filter on engine cover panel.
3. Loosen hose clamp (1), and pull hose (2) from intake pipe. (Scheme 9) Lay hose over to right.
4. Using chalk or felt pen, mark serpentine belt direction of rotation. To loosen belt, turn tensioning element in direction of arrow. (Scheme 5)
5. Tensioner may be secured with a mandrel (4.5 mm diameter and 55 mm long). On vehicles without headlight washer system, secure tensioner with special tool (3090). (Scheme 6) Remove belt.
6. For better access to electrical connections on generator, loosen hex bolts (1), and slightly swivel bracket (2) upwards. (Scheme 10)
7. Unscrew nut, and disconnect terminal 30/B+ wire (2). (Scheme 11) Unplug terminal 61 connector (1). Loosen two generator securing bolts, and lift out generator.
8. To install, reverse removal. Ensure belt is correctly routed and properly seated. Tighten all bolts to specification. See «TORQUE SPECIFICATIONS»(/audi/tt/8n-1998-2003/remont/charging-system/#generators-regulators__torque-specifications).

Scheme 8

Scheme 9

Scheme 10

Scheme 11

Removal & Installation (With Freewheel)

1. Remove generator. See «GENERATOR»(/audi/tt/8n-1998-2003/remont/charging-system/#generators-regulators). Using Adapter (3400), counter-hold securing nut. Turn generator shaft clockwise to remove.
2. To install, turn generator shaft counterclockwise. (Scheme 12) Tighten to specification. See «TORQUE SPECIFICATIONS»(/audi/tt/8n-1998-2003/remont/charging-system/#generators-regulators__torque-specifications). Clip protective cap onto freewheel pulley.

Scheme 12

Removal & Installation (Without Freewheel)

1. Remove generator. See «GENERATOR»(/audi/tt/8n-1998-2003/remont/charging-system/#generators-regulators). Using Socket (3310), counter-hold securing nut. (Scheme 13) Turn generator shaft clockwise to remove.
2. To install, turn generator shaft counterclockwise. Tighten to specification. See «TORQUE SPECIFICATIONS»(/audi/tt/8n-1998-2003/remont/charging-system/#generators-regulators__torque-specifications).

Scheme 13

VOLTAGE REGULATOR

Note. Manufacturer does not provide specific procedures for removal and installation of voltage regulator. As an aid in removal and installation (Scheme 14)or (Scheme 15).

Scheme 14

Scheme 15

OVERHAUL

Note. Manufacturer recommends replacing generator as an assembly. Overhaul procedures are not available.

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

Scheme 16

WIRING DIAGRAMS

Note. See CHARGING SYSTEM in appropriate SYSTEM WIRING DIAGRAMS article in ELECTRICAL.

See also:
• WIRING DIAGRAMS
• SPECIFIC GRAVITY SPECIFICATIONS
• VOLTAGE REGULATOR
• TORQUE SPECIFICATIONS