8HP45 Tcc Solenoid, remanufactured and ready to install. Fits the 8HP45. Ships fast from the USA.
If your BMW 2 Series, 3 Series, 5 Series, M5 or X3 with the ZF eight-speed has started to shudder on a light-throttle cruise, holds higher revs on the highway than it used to, or has logged a converter clutch fault, the torque converter clutch solenoid in the mechatronic unit is one of the first parts to suspect. This listing is a single remanufactured TCC solenoid for the first-generation 8HP45 family, with interchange listed to the 8HP55 and 8HP70. It replaces one solenoid, not the whole valve body, which is the economical fix when testing points to this one position.
The 8HP45 is fully electronic. Every shift element and the converter clutch are fed by electronic pressure regulators bolted to the valve body under the mechatronic circuit board. The converter clutch regulator is identified in the Sonnax solenoid chart as EDS-2 TCC on BMW units, SOL TCC on the Chrysler 845RE version, and EPC-TCC (N443) on the Audi 8HP55, and it sits in position B on the valve body. The transmission module sends it a varying current, and the solenoid turns that into a controlled pressure on the converter clutch valve (ZF calls it WK-V). That pressure decides how gently the lockup clutch applies, how much it is allowed to slip for smoothness, and when it releases. A solenoid that sticks, leaks internally or drifts out of calibration gives the module a clutch that will not do what it commands.
Shudder on an 8HP is not always the solenoid. Sonnax's valve body layout ties the same converter shudder, TCC slip, damaged linings and poor fuel economy to wear in the TCC valve bore itself, and low fluid from a leaking connector sleeve or cooler lines can produce the same complaint. Check the fluid level properly first (a dipstick-free transmission is filled and checked at the case plug at temperature), make sure the module software is current, then read the fault memory. With the mechatronic out and the board off, Sonnax's ZF8-ZIP booklet gives about 5.0 ohms at 68 F for these solenoids, measured with a meter that applies less than 0.6 volts. A reading far off that number, or a solenoid that is noisy or sticky on a bench driver, confirms it. Our ZF8HP solenoid symptoms guide and the BMW 3 Series shift problems guide walk through the order of checks.
The source listing names BMW F22, F30, G31, F90 and G01 chassis and the 8HP45, 8HP55 and 8HP70. Be careful here: ZF moved to a second generation (8HP50, 8HP75, 8HP95 and the Chrysler 850RE) during those model years, and Transmission Digest's identification guide notes that first- and second-generation solenoid caps and snout diameters do not interchange. Later G-chassis cars in particular often carry second-generation units. Pull your old solenoid and compare the cap, snout and connector side by side, or send us your year and VIN before ordering so we can check it. All of our ZF eight-speed parts are grouped on the ZF 8HP collection page.
The solenoids live inside the mechatronic, so the job means draining the fluid, removing the pan, unplugging the connector sleeve and lifting the mechatronic out. On most BMWs the plastic pan carries the filter and its gasket, so plan on a new pan and filter rather than reusing the old one. Swap only the TCC position, keep every other solenoid where it came from, and torque the valve body hardware evenly so the plates do not warp. Replace the connector sleeve seals while it is apart, since a weeping sleeve is a known 8HP pressure leak. Refill with ZF Lifeguard 8 or an approved equivalent and set the level hot at the fill plug. Clear codes and drive through several lockup cycles so the module can learn the new part.
If more than one solenoid tests weak, the 9-piece 8HP45/8HP70 solenoid kit renews the whole set in one job, and if the bore wear Sonnax describes is present, a complete 8HP45 valve body with solenoids may be the better repair.
| Fits | 8HP45 |
| Part type | Tcc Solenoid |
| Condition | Remanufactured |
| Brand | OEM |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
It is listed for the first-generation 8HP45, 8HP55 and 8HP70. Second-generation solenoids use different caps and snout diameters, so compare your old part to the photo or send us your year and VIN before ordering.
One solenoid. The listing covers a single converter clutch pressure control solenoid for the TCC position on the valve body.
Yes. Shudder as lockup applies, higher cruise RPM and converter clutch codes are the classic signs, but a worn TCC valve bore or low fluid can cause the same thing, so check those too.
ZF specifies its Lifeguard 8 fluid for the 8HP family. Use that or an approved equivalent and set the level hot at the case fill plug.
Clear the codes and let the module adapt by driving through repeated lockup cycles. Many shops also run the adaptation routine in their scan tool or dealer software for the transmission.
