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ZF 6HP (caja automática de convertidor de par, 6 velocidades)Urgency: Garage soon

Automatic gearbox fault warning in the ZF 6HP gearbox: causes

In the ZF 6HP gearbox, 2 documented faults may be the cause: valve body and mechatronic failure: erratic shifts or a locked-up gearbox and jerking and harsh shifts from converter wear and ageing oil.[1]

What to do now

Garage soon

Stop the car somewhere safe. Sometimes the warning disappears when you switch off and on again, but the fault stays logged: have it diagnosed before it gets worse.

What it means

On automatic and dual-clutch gearboxes, the warning can show up as a dedicated warning light, as a flashing gear indicator or as a message on the dashboard. It is often accompanied by a limp mode with only a few gears available.

Gearbox warning: causes in all cars

7 sourcesHow we work

Gearbox faults that cause it

From most to least important. Under each fault, how the symptom shows up. Check the affected years and versions on each page.

  1. Source for the symptom[1]

  2. Source for the symptom[1]

How much it can cost

Depending on the cause, repair at an independent garage ranges from €150[3][4] (jerking and harsh shifts from converter wear and ageing oil) to €400[3][4] (jerking and harsh shifts from converter wear and ageing oil), including VAT.

Most serious fault among the possible causes: High severity

Other common causes: gearbox warning

Besides the documented faults of the ZF 6HP, these are the most common causes on any car according to the sources.

  • Degraded ATF oil or insufficient level[5][6]Common
  • Clogged valve body (mechatronic unit)[6]Common
  • Electrohydraulic unit or synchronisation fault[5]Possible
  • Low battery voltage[5]Possible
  • Leak or lack of pressure in the hydraulic circuit[5]Possible
  • Torque converter or internal clutch disc[5]Uncommon

What to check first

  1. Note the colour and symbol of the warning light, whether the gear indicator flashes and how the gearbox behaves: jerking, gears that won't go in, high revs or only one gear available.[5][6]
  2. With the car stationary in a safe place, check the condition of the 12 V battery: RACE includes low voltage among the causes of a gearbox that doesn't work.[5]
  3. See when the ATF oil and filter were last changed: RACE speaks of roughly every 100,000 km on torque converter gearboxes and every 90,000 km on CVTs, as the manufacturer indicates.[5][6][7]
  4. Check for oil stains under the car, since a leak in the hydraulic circuit lowers the pressure.[5]
Complete guide: automatic gearbox fault warning

Cars with the ZF 6HP gearbox

Open yours to see only the faults that affect it according to its years and versions.

Frequently asked questions

Gearbox warning in the ZF 6HP: what could it be?

In the ZF 6HP gearbox, 2 documented faults may be the cause: valve body and mechatronic failure: erratic shifts or a locked-up gearbox and jerking and harsh shifts from converter wear and ageing oil. Each fault has its own page with the affected years and versions, the cause and how to check for it.

Gearbox warning in the ZF 6HP: is it serious?

Urgency: garage soon. Stop the car somewhere safe. Sometimes the warning disappears when you switch off and on again, but the fault stays logged: have it diagnosed before it gets worse. The most serious fault that causes it on this engine has high severity.

Gearbox warning in the ZF 6HP: how much does it cost to fix?

It depends on the cause: at an independent garage, from €150 (jerking and harsh shifts from converter wear and ageing oil) to €400 (jerking and harsh shifts from converter wear and ageing oil), including VAT.

Sources

Every fact on this page links to its source. If you find an error, let us know.

  1. Fiabilité Audi A6 (2004-2010), pannes et témoignagesFiches-auto.fr · Owners' forum · consulted 27 September 2026 · in French
  2. Fiabilité Audi A8 (2002-2010), pannes et témoignagesFiches-auto.fr · Owners' forum · consulted 27 September 2026 · in French
  3. El aceite de la caja de cambios automática que el fabricante no cambia: evita una avería de 3.000 eurosMotor16 · Motoring press · published 26 September 2026 · consulted 27 September 2026 · in Spanish
  4. El mantenimiento de la caja de cambios que evita una avería de más de 2.000 eurosMotor16 · Motoring press · published 21 September 2026 · consulted 27 September 2026 · in Spanish
  5. No entran las marchas del cambio automático, ¿cuáles son las razones?RACE · Motoring press · published 23 June 2023 · consulted 29 October 2026 · in Spanish
  6. Problemas y mantenimiento en la caja de cambios automáticaRACE · Motoring press · published 10 September 2020 · consulted 29 October 2026 · in Spanish
  7. Así es una caja de cambios CVT automáticaRACE · Motoring press · published 30 May 2023 · consulted 29 October 2026 · in Spanish