Multitronic gearbox: how the Audi CVT works and which problems to watch for

The Multitronic gearbox is Audi’s continuously variable automatic (CVT), used in front-wheel-drive A4, A5 and A6 models. A steel link chain runs between two adjustable pulleys, and wet multi-plate clutches handle pulling away. Most Multitronic problems, such as judder, jerking or limp mode, start in those clutches, the control unit or the hydraulic control.

If you drive an older Audi with Multitronic, you have probably read the horror stories. Some are deserved. But a jerk when pulling away does not mean the chain is about to snap or that you need a complete gearbox. At ATR Transmissies in Montfoort we see the same pattern often: the real cause is a worn clutch pack, a control unit that is failing or a gearbox that has lost its adaptation, and each of those can be found by measuring before anything is replaced.

What is the Multitronic gearbox?

The Multitronic is Audi’s own version of a CVT gearbox: a continuously variable transmission. A conventional automatic switches between fixed gears. The Multitronic changes its ratio smoothly and without steps, so the engine can stay at its most efficient speed and the car pulls away without the small jolt of a gear change. Audi launched it in late 1999 on the A6 and developed and built it together with the drivetrain specialist LuK.

Most drivers know it from the gear lever or the instrument cluster: P, R, N, D and S, plus a tiptronic-style manual mode. In manual mode the Multitronic simulates fixed steps; later versions offer eight.

Which Audis have a Multitronic?

You find the Multitronic in Audi models with a longitudinally mounted engine and front-wheel drive:

• Audi A6 (where it was launched)
• Audi A4, including the Cabriolet
• Audi A5 (the 8T was the last model sold with it)
• SEAT Exeo, which shares its platform with the A4

The Multitronic was never offered with quattro four-wheel drive, and it does not fit transverse-engined cars such as the A3. A quattro Audi of the same era has a conventional tiptronic automatic or a dual-clutch S tronic instead. In 2014 Audi announced it would replace the Multitronic with S tronic dual-clutch gearboxes, and the next-generation front-wheel-drive A4 and A5 moved to a seven-speed S tronic.

01J, 0AN and 0AW: the Multitronic versions

Specialists distinguish three Multitronic gearbox codes: 01J, 0AN and 0AW. The original 01J could handle up to 310 Nm of torque; the later 0AW was developed for up to 400 Nm and is the eight-step version. The difference matters for parts, the control unit and the repair route, so the gearbox code is one of the first things we check. You find it on the gearbox and in the vehicle data; our guide on how to tell which automatic gearbox you have explains where to look.

How does the Multitronic gearbox work?

The Multitronic has three main parts: a variator that sets the ratio, wet clutches that let the car pull away and reverse, and an electronic control unit that runs both through hydraulics.

A chain that pulls, not a belt that pushes

The heart of the gearbox is the variator: two pairs of conical pulleys with a narrow steel link chain between them, bathed in oil. According to Audi the chain has more than 1,000 individual links. One half of each pulley can slide on its shaft. When the halves move together, the chain runs on a larger radius; when they move apart, it runs on a smaller one. Changing those two radii against each other gives every ratio between the lowest and the highest, without steps.

People often call this a belt, but it is not. Most CVTs use a steel push belt whose elements push each other forward. The Multitronic chain transfers the force through tension, by pulling. That makes it a different gearbox from, for example, a Nissan or Toyota CVT, with its own wear points and its own repair route.

Pulling away: wet multi-plate clutches, no torque converter

Every automatic needs something to disconnect the engine when you stand still. Most automatics and many CVTs use a torque converter, a fluid coupling. The Multitronic does not. It uses wet multi-plate clutches, controlled electro-hydraulically: a forward clutch for driving off, and a separate clutch that works with a planetary gear set to give reverse.

Those clutches do the work a torque converter does in other gearboxes, and they take a lot of it in stop-start city traffic, when manoeuvring and when pulling away on a hill. Earlier gearboxes had six clutch plates and later ones seven. That is why judder or jerking when pulling away so often points to the clutches or their control, and much less often to the chain.

A control unit matched to your car

The Multitronic’s transmission control unit controls the clutches and the pulleys. It is not a universal part. According to Ross-Tech’s technical documentation, a replacement unit must be ordered by vehicle identification number (VIN) because its programming depends on the engine, and it must match the gearbox’s six-plate or seven-plate clutch version. Fitting the wrong unit gives, in their words, “undesirable results”. After replacement the unit has to be coded and the gearbox has to complete an adaptation drive.

In practice this means a cheap used control unit from another Audi is a gamble. It may fit the connector and still be wrong for your car.

Multitronic vs S tronic and DSG

The Multitronic is not the same as an S tronic or DSG gearbox. S tronic and DSG are dual-clutch gearboxes: two gearboxes in one housing with real gears and two clutches that take turns. The Multitronic is a CVT with no fixed gears at all.

Read more about the dual-clutch alternative in our article on Audi S tronic problems and about the Volkswagen equivalent in DSG problems.

Common Multitronic gearbox problems

A well-maintained Multitronic can last a long time, but it has a recognisable set of weak points. In the United States, owners even won a class action in 2013 over alleged manufacturing and design flaws. These are the Multitronic gearbox problems we come across most often.

Judder or jerking when pulling away

This is the complaint we hear most: the car shudders, jerks or “bites” unevenly when pulling away and at low speed, often worse when the gearbox is warm. Usually the forward clutch pack is wearing, the fluid has aged so the clutch is no longer controlled smoothly, or the stored adaptation values no longer match the clutch. Caught early, this is often still very repairable.

Limp mode, a flashing PRNDS display or no drive

If the gear display (PRNDS) flashes, power drops and the car feels stuck in one ratio, the control unit has detected a fault and gone into limp mode to protect the gearbox. Repair specialists report control unit faults on the Multitronic with symptoms such as a flashing PRNDS display, loss of drive or reverse, and a gearbox that drops out of drive when hot. A sensor or an electrical signal can also be behind it. Reading out the gearbox shows which fault code is stored; see our overview of transmission fault codes and the specific P0607 fault code on the Audi Multitronic.

Slipping and worn clutch packs

As the wet clutch packs wear, you notice slipping (revs rising without matching acceleration), vibration and weaker pulling away. The clutches are wear parts. Replacing them in a targeted way can often solve the complaint without a complete overhaul, provided the rest of the gearbox is in good condition.

Valve body and sensor faults

The Multitronic relies heavily on sensors that measure speeds and pressures, and on the hydraulic valve body that moves the pulleys and applies the clutches. When a sensor sends an implausible signal or a valve no longer regulates properly, the gearbox reacts nervously, hesitates or does not pull away properly. If you recognise that behaviour, also read about an automatic gearbox that is not shifting properly.

Noise from the variator or bearings

A whine, hum or grinding noise that changes with road speed can point to wear on bearings, the pulleys or the chain. This is less common than the clutch and control unit complaints, but it is the one you should not drive on with, because debris from wear ends up in the fluid and spreads through the gearbox.

Symptom table: what your Multitronic may be telling you

Use this table as a guide to likely causes, not as a diagnosis.

Does your complaint not fit? Find out what your symptom could mean in our guide to signs of a failing gearbox.

Maintenance: fluid and adaptation

Fresh fluid at the right time prevents many Multitronic complaints, because the hydraulics and the clutch packs keep working cleanly and smoothly. Postponed fluid changes are one of the most common reasons for early wear. The Multitronic needs its own CVT fluid specification; fluid for another make of CVT does not belong in it. Our article on CVT maintenance explains why “lifetime fill” does not mean the fluid never needs changing.

The second part of maintenance is less known: adaptation. The control unit learns how the clutches engage and stores those values. After a fluid change, a clutch repair or a control unit replacement, the gearbox has to complete a defined adaptation drive, with the fluid at operating temperature (Ross-Tech gives 60 to 90 °C). A gearbox that has not adapted properly can judder even when the hardware is fine. We always finish a Multitronic job with that adaptation and a test drive.

Multitronic repair: targeted repair or a new gearbox?

In most cases a Multitronic does not need a complete replacement gearbox. A worn clutch pack, a faulty sensor, a valve that does not regulate properly or a failing control unit can be repaired in a targeted way. Only when the variator, the chain or the bearings are damaged does an overhaul or a remanufactured gearbox come into the picture. A replacement control unit then has to be correctly programmed and coded.

What a Multitronic repair costs depends on the gearbox code, the fault the diagnosis finds, whether a targeted repair is possible, and which parts are needed. That is why we work with a price on request: after reading out and diagnosing, you receive a concrete price indication before we repair anything. Contact us for a price indication based on your registration number and complaint.

How ATR Transmissies handles a Multitronic complaint

ATR Transmissies always approaches a Multitronic in a targeted way:

1. Book your car in. Send your registration number, the complaint and any fault codes or messages you have seen.
2. Independent basic diagnosis. We read out the gearbox, check the fault memory, the live data and the adaptation status, assess the fluid and take a test drive. That tells us whether the problem is electrical, hydraulic or mechanical.
3. A clear choice, then the repair. You hear what we found and what we advise before we start. After the repair the gearbox completes its adaptation drive, and we test the car again.

Our starting point is to repair what is actually worn, not to swap a gearbox because the symptom sounds serious. ATR makes some parts in-house and researches materials and tolerances, which helps when a Multitronic part is hard to source. Want to know what is going on with your Audi? Book your car in.

For garages

Do you have an Audi with a Multitronic complaint and doubts about the cause? With ATR Remote we can read and assess the gearbox remotely, so you know before removing anything whether it is the control unit, the clutches or something else.

Frequently asked questions about the Multitronic gearbox

Is the Audi Multitronic gearbox reliable?

The Multitronic has a mixed reputation. It drives smoothly and efficiently, but the clutches and the control unit are known weak points, and neglected fluid shortens its life. A Multitronic with a documented service history and no judder is a very different proposition from one with an unknown past.

Is Multitronic the same as DSG?

No. DSG (S tronic at Audi) is a dual-clutch gearbox with real gears and two clutches. The Multitronic is a CVT: a chain between two adjustable pulleys, without fixed gears. They feel different, wear differently and are repaired differently.

Is CVT or DSG better?

Neither is better in every situation. A CVT such as the Multitronic is smooth and comfortable in steady driving and town traffic. A dual-clutch gearbox shifts faster and feels sportier, and copes with more torque. What matters most for either is maintenance and dealing with complaints early.

Does the Multitronic have a belt or a chain?

A chain. The Multitronic uses a steel link chain of more than 1,000 links that pulls between two conical pulleys. That is different from most CVTs, which use a steel push belt. The chain is strong, but the gearbox does depend on the right fluid and a well-working control unit.

Can a Multitronic be repaired without a complete overhaul?

Often, yes. Complaints such as judder when pulling away or limp mode usually come from the clutch pack, sensors, the valve body or the control unit. Those can be dealt with in a targeted way, so a complete overhaul can often be avoided. A proper diagnosis tells you which case you have.

Why does my Audi with Multitronic go into limp mode?

Because the control unit has detected a fault and protects the gearbox by limiting power and ratio. The cause is often a sensor, an electrical signal or the control unit itself, sometimes a clutch or pressure problem. Reading out the gearbox shows which fault code is stored.

Which Audi should I stay away from?

We do not give a blacklist. With a used Audi Multitronic, the history matters more than the model year: ask for proof of fluid changes, test drive it warm, and check for judder when pulling away and a flashing PRNDS display. Not sure? Have the gearbox read out before you buy.

How much does an Audi gearbox repair cost?

That depends on the gearbox code, what the diagnosis finds, whether a targeted repair is possible and which parts are needed. A clutch or control unit repair is a very different job from replacing the gearbox. Contact us for a price indication based on your registration number and complaint.

A smooth gearbox that rewards a careful diagnosis

The Multitronic gearbox is a clever, smooth CVT, but its clutches, control unit and fluid need attention. Judder when pulling away, limp mode or a flashing PRNDS display are signals you should not ignore, and they can often be fixed in a targeted way rather than with a new gearbox.

Not sure what is causing your Multitronic complaint, or whether a repair is enough? Book your car in with ATR Transmissies in Montfoort. We read out your Audi, also remotely for garages, and repair in a targeted way so you do not pay for an overhaul you do not need.