20 Most Recent 1999 Audi A4 - Page 2 Questions & Answers

Certainly. Get the Haynes Repair Manual on your vehicle from the local Auto Parts store and it will explain the steps in each service and identify any special tools that may be required.

Anti-Lock Braking System (ABS) Purpose Anti-lock brake systems (ABS) - generally also referred to as anti-lock systems (ALS) - are designed to prevent the vehicle wheels from locking as a result of the service brake being applied with too much force, especially on slippery road surfaces. The idea is to maintain cornering forces on braked wheels to ensure that the vehicle or vehicle combination retains its driving stability and manoeuvrability as far as physically possible. The available power transmission or grip between tyres and carriageway should also be utilised as far as possible to minimise the braking distance and maximise vehicle deceleration. Why ABS? Although today commercial vehicle brakes are designed to a very high technical standard, braking on slippery roads often results in potentially dangerous situations. During full or even partial braking on a slippery road it may no longer be possible to fully transfer the braking force onto the road due to the low coefficient of friction (friction coefficient (k)) between the tyres and the carriageway. The braking force is excessive and the wheels lock up. Locked wheels no longer provide any grip on the road and are almost incapable of transferring any cornering forces (steering and tracking forces). This often has dangerous consequences: - The vehicle becomes unsteerable - The vehicle breaks away in spite of countersteering, and starts to swerve. - The braking distance is significantly increased - Tractor-trailer combinations or semitrailer trains may break away or jackknife. Load sensing valve influence On dry roads today's load sensing valves (ALB) alone are often capable of preventing the wheels from locking if the vehicle is unladen; they also help the driver to effectively grade the braking process on wet road surfaces, but they are unable to prevent locking as such (no slip monitoring). In addition, they are unable to counteract any overreactions on the part of the driver, or any variances in frictional or adhesion coefficients which may apply to different sides of the vehicle, or indeed to its different axles (?-split road surfaces). Benefits of ABS: Only the Anti-Lock Brake System (ABS) - guarantees stable braking characteristics on all road surfaces. - maintains steerability and generally reduces the braking distance - prevents vehicle combinations from jackknifing - reduces tyre wear. Limits of ABS Although ABS is an effective safety device, it can not suspend the limits defined by driving physics. Even a vehicle fitted with ABS will become uncontrollable if driven too fast around a corner. So ABS is not a licence for a maladjusted style of driving or failure to observe the correct safety distance. 4 ABS Training Anti-Slip Regulation (ASR) Anti-Slip Regulation (ASR) Why ASR? Increasing the engine output (accelerating) on a slippery road surface can easily lead to the maximum adhesion on one or all powered wheels being exceeded causing them to spin, especially if the vehicle is unladen or partially laden. Spinning wheels when driving off or accelerating represent a safety risk just like locked wheel do when braking. Reasons - Wheels that spin transfer just as little cornering force as locked wheels. - They also no longer transfer any tractive power onto the road. Consequences - Vehicles that do not move or get stuck. - Vehicles that can no longer be steered, jackknife on uphill uphill gradients, or swerve in corners. Benefits of ASR ASR prevents the powered wheel from spinning and provides the following benefits: - Tractive power and cornering forces are maintained. - Stable driving behaviour is ensured when moving off, accelerating and negotiating corners on slippery roads. - The indicator lamp (if installed) is used to warn the driver of slippery road conditions. - Tyre wear is reduced to a minimum, and the motor vehicle's drive train protected - The risk of accidents is further reduced. ASR and ABS: ASR represents a worthwhile addition to an ABS-controlled braking system. All that is required to turn ABS control into full ABS/ASR control is an ECU with the additional ASR function and a few additional components for controlling the differential brake and the engine. This why ASR is only available in combination with ABS. Even a differential lock for off-road use and ASR do not exclude but complement each other. Limits of ASR The traction capacity of an all-wheel driven commercial vehicle can not be achieved by a motor vehicle with only one driving axle - not even with optimal ASR.

I do not understand what you mean. If the engine starts it is turning over. Turning over means the engine turns not that it starts. So the engine cranks but does not start? You need to check the crank position sensor. It should have 3 wires at the connector. 1 is power 12V, 1 is ground and the other is the square wave signal. with a volt meter make sure you have power at the wire closest to the curves side of the connector. Check resistence to ground on the wire closest to the square end of the connector. You cannot check the signal with out a lab scope or graphing multi meter. If power and ground are good you need a mechanic.

Get a Chilton/Haynes repair manual that covers this vehicle. It will, with pictures, show you where fuel filter is and how to change it.

The throttle body itself is just a casting and should not need to be replaced. The throttle within controls the amount of air going into the engine. It should not need to be replaced. The critical part that is sending information to the ecu (computer) is the Throttle possition indicator. if it has come up as an error code it could be bad contacts. Corrosion causes funny problems. Scrape the contacts to bright metal, reassemble check codes again. Still a problem replace the sensor.

You often have to replace both tail light bulbs and replace them with identical bulbs. I prefer the nickel-plated bulbs (rather than the brass base) with the elliptical contacts, generally these are marketed as 'european' bulbs.

All 4 wire O2 sensors are compatible in function. The only difference is the plug for the wiring loom.
A B5 A4 and a C4 A6 should have the same plug...

I wouldn't use a second hand O2 sensor though.., always buy new.

Very cool - sorry it took awhile to get back here but I'm glad you found it.

check for a broken rear engine mount as it may have failed from the torque reaction and now will not allow the shifter to work.

First step check the fluid level (engine warmed up and in neutral. If trans has enough oil but smells or looks burnt you have issues that require a transmission specialist who will most likely rebuild or replace the entire unit

vw/audi recon its in for life,but i would change at 100k,cant do any harm.....

Check your inner fender liner. May be fastener broke, liner touching wheel when turning.

Autoparts store will look it up for you. For longevity, OEM are platinum. If you don't mind changing them more often, copper plugs work very good. On tune 1.8T (or chipped), I recommend NGK BKRE7E (one step colder than stock) copper plugs, gapped to 0.028 or 0.030 (B5 A4 have weak coils and they 'fade' with age; if misfires are detected, time to change coils (temp fix: even smaller gap).

Are you saying you are loosing coolant and have to top of frequently? What engine do you have? 1.8T or 2.8?

This is an electronic transmission and may have an electrical problem Can\'t tell without more info. However, it will not go into top gear if you are pressing hard on the throttle. try going at highway speed and letting off the throttle It should shift into high gear. If it does not, it is dealer time.

1) Open trunk 2) Remove small round plastic access panel with a flat tip screw driver by prying open 3) Remove flat tip screw holding tail light assembly 4) Remove tail light assembly by pulling outward, careful not to break plastic guide/nub 5) Disconnect wiring connectors 6) Remove plastic housing access plate on back of tail light assembly by twisting/turning tabs until they click and then lift access plate from tail light assembly 7) When viewing the the bulbs, the turn signal bulb is the bottom left bulb 8) Install in reverse order, ensuring tail light seal seats properly during installation

Best advise is to purchase a Chilton/Haynes repair manual for your make/model and year. It has detailed description of how to do this. Even has pictures and diagrams. Also good for all around repairs and maintenance.

It's located on the front cover of your audio manual, 4 digit number. If you do not have the manual, call Audi USA and give them your VIN and verify ownership of vehicle and they will give you the 4 digit code