Seven-piece shift and pressure solenoid set, reference 1068298046, for the ZF 6HP21 and 6HP28 in BMW 128i and 335i, Audi and Land Rover models.
A BMW 335i or 128i that bangs into Reverse, a Q5 or S5 that flares between gears, or an LR4 that suddenly holds one gear with a transmission warning on the dash all point at the same place: the solenoid bank inside the ZF 6HP21 or 6HP28 mechatronic. This seven-piece set, reference 1068 298 046, replaces those solenoids together so you are not paying for the valve body to come out a second time when the next tired solenoid gives up.
The 6HP21 and 6HP28 are second-generation members of the ZF 6HP family. The transmission computer never applies a clutch directly. It sends a controlled current to a solenoid, the solenoid converts that current into an oil pressure signal, and that signal moves the valve that fills or exhausts a clutch. Most of the solenoids in this unit are pressure regulators, so the computer expects a precise pressure for every milliamp it commands. Second-generation units dropped the MV1 solenoid used on the earlier 6HP19 and 6HP26 and split the D and E clutch control between two normally-vented solenoids, EDS6 and EDS4. That change is why a first-generation set is the wrong part here even where a solenoid would physically drop into a bore.
The set in this listing uses the second-generation color pattern: two blue caps, two orange caps and three yellow caps. Sonnax notes that Gen 2 units added orange connectors at the EDS1 and EDS2 positions, which is a quick way to confirm you are looking at the right family when you lay your old solenoids next to these.
Check fluid level and condition first, then unplug the connector at the transmission case and look for oil inside it. A leaking connector sleeve can push fluid into the plug and set faults that look exactly like a dead solenoid. If the plug is dry, test each solenoid off the car. Sonnax gives 5 to 6 ohms at 68 degrees F as the resistance spec, but a solenoid can pass that and still leak internally, so a vacuum test on a matching manifold is the check that actually finds the bad one. Our ZF6HP shift solenoid testing guide walks through both tests, and the pressure control solenoid guide explains how to tell a line pressure problem, which hurts every shift, from a single clutch circuit that only spoils one.
The listing covers the ZF 6HP21, 6HP21X, 6HP28, 6HP28X and 6HP28A, with applications given as BMW 128i, 335i, 335xi and 335d; Audi A4 Quattro, Q5 and S5; and Land Rover LR4 and Range Rover Sport 2010-2013. Several of those model lines used a first-generation 6HP19 in earlier build years, so go by the tag on the side of the transmission rather than the badge on the trunk. If the tag reads 6HP19, 6HP26 or 6HP32, you need a Gen 1 kit such as the ZF 6HP19 7-piece solenoid set. Not sure which you have? Send your year and VIN and we will check it. The full range of parts for this family is in our ZF 6HP collection.
If the pan is full of friction material or the fluid smells burnt, new solenoids will not cure it; the clutches are already worn and the unit needs a rebuild.
| Fits | ZF 6HP21, 6HP21X, 6HP28, 6HP28X, 6HP28A |
| Reference | 1068 298 046 |
| Pieces | 7 solenoids |
| Applications | BMW 128i / 335i / 335xi / 335d, Audi A4 / Q5 / S5, Land Rover LR4, Range Rover Sport 2010-2013 |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
It depends on which transmission your car was built with. Some early 3 Series cars used the first-generation 6HP19, which takes a different solenoid set. Read the tag on the transmission case: 6HP21 or 6HP28 means this kit fits, 6HP19 means you need the Gen 1 set. Send your VIN if you want us to confirm.
All of them, in most cases. The solenoids share the same fluid and heat history, so when one has worn internally the others are usually close behind, and the labor to pull the mechatronic is the same either way.
Yes. The transmission computer stored corrections for the old worn solenoids. Clear codes and reset adaptations with a scan tool that supports your make, then drive gently through all gears so it can relearn.
ZF specifies LifeguardFluid 6 for this family. Some manufacturers sell it under their own label. Fill and check the level at the fill plug with the engine running and the fluid at the specified check temperature.
Not directly. Oil in the connector is a leaking sealing sleeve, a known wear item on these units. It can corrode pins and set solenoid faults on its own, so replace the sleeve and clean the connector before you judge the solenoids.
