Carsieve At a glance
- What it is: a ZF six-speed torque-converter automatic, called Steptronic by BMW and tiptronic by Audi. The 6HP19 and 6HP26 are the first generation. The 6HP21 and 6HP28 followed from about 2007.
- Main faults: mechatronic and solenoid faults, worn bushings, and torque converter shudder.
- Reliability: 2/5, because the same faults recur across variants.
- DIY: 1/5, because fault checks and the adaptation reset need a dealer-level scanner (ISTA on a BMW).
- Prefer: a car with fluid and pan service records and a clean scan.
- Avoid: a car that shudders at steady speed, jerks or hangs in gear, shows BMW codes 4F85 or 4F8F, or has no proof of fluid changes.
Known issues
| Issue | Affects | Typical km | Repair cost |
|---|---|---|---|
| Mechatronic and solenoid faults | All 6HP cars, worst when overheated | 100,000 to 150,000 km | No confirmed price |
| Worn bushings | All 6HP cars, Audi drum bushings and 6HP21 input shaft | 60,000 to 150,000 km | No confirmed price |
| Torque converter shudder | All 6HP cars | 120,000 to 150,000 km on Audi quattro units up to 2009 (Kolesa.ru, Audi A6 C6) | No confirmed price |
Before you buy
- Read the fault memory with ISTA or a BMW or Audi scanner. Bad result: BMW codes 4F85, 4F8F or 4F83, or a past limp mode. A scanner is needed.
- Ask for fluid and pan service records. Bad result: no change in the last 60,000 to 100,000 km, or no adaptation reset afterwards. Dirty oil adds to mechatronic wear.
- Drive 15 minutes in town, then under load. Bad result: slipping, flaring, or jerks on 2-3 and 3-4.
- Hold a steady light throttle at 60 to 80 km/h. Bad result: a shudder or vibration, which points to the torque converter lock-up clutch.
- Drive under load in 4th and 5th. Bad result: slip under load or jerks on shift, which points to worn bushings.
Models with this gearbox
| Brand | Model | Generation | Production years | Power | Engine codes | ADAC versions |
|---|---|---|---|---|---|---|
| Audi | A4 | B6 | 2003–2005 | 344 PS (253 kW) | BBK | 3 |
| Audi | A4 | B7 | 2004–2009 | 200–344 PS (147–253 kW) | ASB, AUK, BBK, BKN, BWE | 16 |
| Audi | A4 | B8 | 2007–2011 | 240–265 PS (176–195 kW) | CAL, CCW | 31 |
| Audi | A5 | 8F/8T | 2007–2011 | 240–354 PS (176–260 kW) | CAL, CAU, CCW | 6 |
| Audi | A6 | C6 | 2004–2008 | 163–580 PS (120–426 kW) | ASB, AUK, BAT, BDX, BMK, BPP, BUH, BVJ, BXA, CAN | 34 |
| Audi | A6 | C6 facelift | 2008–2011 | 190–580 PS (140–426 kW) | BUH, BVJ, BXA, CAJ, CAN, CCE, CDY | 18 |
| BMW | 1er-Reihe | E87 | 2004–2007 | 129–265 PS (95–195 kW) | N46B20B, N47D20C, N52B30A | 5 |
| BMW | 1er-Reihe | E81/E87/E82/E88 facelift | 2007–2012 | 122–306 PS (90–225 kW) | N43B16A, N43B20A, N47D20C, N47D20D, N52B30A, N54B30A | 81 |
| BMW | 1er-Reihe | E82/E88 facelift 2 | 2011–2013 | 143–218 PS (105–160 kW) | N43B20A, N47D20C, N47D20D, N52B30A | 44 |
| BMW | 3er-Reihe | E90/E91/E92/E93 | 2005–2010 | 129–306 PS (95–225 kW) | 306D3, 306D5, N43B20A, N45B20A, N46B20B, N47D20C, N52B25A, N52B30A, N53B30A, N54B30A, N57D30A | 118 |
| BMW | 3er-Reihe | E90/E91/E92/E93 facelift | 2008–2014 | 143–306 PS (105–225 kW) | 306D3, 306D5, N43B20A, N45B20A, N47D20C, N53B30A, N54B30A, N55B30A, N57D30A | 200 |
| BMW | 5er-Reihe | E60/E61 | 2003–2007 | 163–367 PS (120–270 kW) | M47D20TÜ2, M54B22, M54B25, M54B30, M57D25TÜ, M57D30OL, M57D30TOP, M57D30TÜ, N52B25A, N52B30A, N62B40A, N62B44, N62B48B | 32 |
| BMW | 5er-Reihe | E60/E61 facelift | 2007–2010 | 163–367 PS (120–270 kW) | M57D30OLTÜ, M57D30TOPTÜ, M57D30UL, N43B20A, N47D20C, N53B25A, N53B30A, N62B40A, N62B48B | 154 |
| BMW | 7er-Reihe | E65/E66 facelift | 2005–2008 | 231–445 PS (170–327 kW) | M57D30TÜ2, M67D44, N52B30A, N62B40A, N62B48B, N73B60A | 14 |
| BMW | 7er-Reihe | F01/F02 | 2008–2012 | 245–407 PS (180–300 kW) | N54B30A, N57D30A, N57D30B, N63B44A | 14 |
| BMW | X1 | E84 | 2009–2012 | 143–258 PS (105–190 kW) | N46B20B, N47D20C, N47D20D, N52B30A | 8 |
| BMW | X1 | E84 facelift | 2012–2015 | 150 PS (110 kW) | N46B20B | 7 |
| BMW | X3 | E83 | 2005–2006 | 218 PS (160 kW) | 306D3 | 1 |
| BMW | X3 | E83 facelift | 2006–2010 | 177–286 PS (130–210 kW) | 306D3, 306D5, N47D20C, N52B25A, N52B30A | 32 |
| BMW | X5 | E53 facelift | 2003–2006 | 218–360 PS (160–265 kW) | M57D30TÜ, N62B44, N62B48 | 11 |
| BMW | X5 | E70 | 2007–2013 | 235–555 PS (173–408 kW) | M57D30TÜ2, N52B30A, N62B48B, S63B44A | 12 |
| BMW | Z4 | E85/E86 facelift | 2006–2008 | 177–265 PS (130–195 kW) | N52B25A, N52B30A | 22 |
| BMW | Z4 | E89 | 2009–2011 | 204–258 PS (150–190 kW) | N52B25A, N52B30A | 2 |
In detail
Mechatronic and solenoid faults
Symptoms. Harsh or delayed shifts, a jolt on up-shifts, slipping, and limp mode with the gear display lost. Fault codes 4F85, 4F8F and 4F83 are logged.
Cause. The mechatronic (the control unit and valve block) wears from heat. Oil above 110 C in summer or in traffic damages the solenoids. Debris from the torque converter clutch clogs them. A crack in the board solder at the valve body screws can also cause faults.
Which cars. All 6HP variants. Early units failed by about 100,000 km. Solenoids fail from 100,000 to 150,000 km.
Fix. Replace the solenoids one at a time after a bench test, not the whole set. Or fit a new mechatronic, or repair the board by microsoldering. Reset the adaptations afterwards.
Cost. No garage price in EUR or GBP.
Sources: KFZ Dietrich, BMW GA6HP service, AKPPHELP, ZF 6HP repair, Otoba, ZF 6HP19, PistonHeads, BMW 530i mechatronics
Worn bushings
Symptoms. Jerks on shifts, slipping on 4th and 5th under load, and loss of oil pressure. One owner on DRIVE2 reports that jerks on hard acceleration are worse on diesels.
Cause. The metal bushings in the pump stator, the input shaft and the drum wear. Oil pressure drops, and the clutch packs slip.
Which cars. All 6HP variants. Za Rulem says Audi drum bushings are the most common Audi fault. Auto.ru says the 6HP21 input shaft has a single bushing that wears quickly. Typical km: 60,000 to 150,000 km. Oil pump wear is reported from 200,000 km.
Fix. Replace the bushings in a major repair, usually as a set. Repair the mechanical part, not only the mechatronic. On some variants the bushings are sold separately, on others only the drum assembly.
Cost. No confirmed price in EUR or GBP.
Sources: DRIVE2, ZF 6HP technical article, Za Rulem, automatic gearboxes, Auto.ru, ZF 6HP21, Otoba, ZF 6HP26
Torque converter shudder
Symptoms. A shudder or vibration at a steady 60 to 80 km/h under light load. Some converters shake at 50 to 70 km/h.
Cause. The lock-up clutch in the torque converter wears. Its friction lining sheds dust that clogs the solenoids. Worn lock-up parts cause jerks and vibration.
Which cars. All 6HP variants. Kolesa.ru gives a lock-up friction life of 120,000 to 150,000 km on Audi quattro units up to 2009. Flushing helps only if it is caught early.
Fix. A new or rebuilt converter.
Cost. No confirmed price.
Sources: KFZ Dietrich, BMW GA6HP service, Otoba, ZF 6HP19, Kolesa.ru, Audi A6 C6, Kolesa.ru, Jaguar XF
Recalls
No recall, TSB or service campaign for the 6HP is stated by the sources. Check open campaigns for your VIN with a BMW or Audi dealer before you buy.
Maintenance
- Fluid and filter. Change every 60,000 to 100,000 km, and sooner with heat, towing or sport driving. BMW calls the fill lifetime, but garages advise regular changes.
- Fluid. ZF Lifeguard Fluid 6, or Shell M-1375.4, about 9.5 litres in total. A drain removes only about 60% of the fluid, so a drain is not a full change.
- Level. Check at 40 C oil temperature, through the overflow pipe.
- After any service or repair. Reset the adaptations with a dealer-level scanner (ISTA on a BMW). The car can jerk for about 1,000 km while it relearns.