722.9 Pressure Control Solenoid

Searching for a 722.9 pressure control solenoid usually means a Mercedes C, E, S, ML or GL Class, or a Sprinter, with the seven-speed 7G-Tronic is shifting hard one day and slipping the next, or has stored a pressure control solenoid code. This listing is a new set of eight 722.9 solenoids, referenced to Mercedes part number 220 277 10 98 (A2202771098), so you can renew every pressure regulator on the conductor plate in one job instead of buying them one at a time.

What the pressure control solenoids do in a 722.9

In the 7G-Tronic every solenoid is a pressure control solenoid. There are no simple on-off shift valves; each solenoid turns an electrical command from the transmission control module into a regulated hydraulic pressure. One sets working pressure for the whole unit, the shifting clutches and brakes each get their own regulator, and one controls torque converter lockup. All eight plug into the conductor plate, which bolts on top of the valve body and carries the built-in control module. Transmission Digest notes that the solenoids are individually serviceable while the conductor plate and module are not, which is why a solenoid set is the normal repair when the hydraulics, not the electronics, are at fault.

Symptoms of a failing 722.9 pressure control solenoid

• Harsh shifts or a hard engagement into Drive or Reverse
• Soft, slipping shifts, most noticeable once the fluid is hot
• Launching from a stop in the wrong gear
• Burnt-smelling fluid from a clutch that has been slipping on low apply pressure
• Pressure control solenoid circuit or performance codes, generic codes in the P0960-P0967 range
• Lockup shudder at steady speed

How to confirm it before buying

ATRA's GEARS Magazine reports that most 722.9 solenoid failures it sees come from the O-rings on the solenoid tips deteriorating and leaking, so the valve does not stroke correctly. That is a real solenoid fault and a set like this fixes it. The trap is that worn regulator valve bores in the valve body produce the same list of symptoms and the same codes. Sonnax describes working pressure regulator bore wear that can drive line pressure either low or high depending on where the bore wears. So scan the module, inspect the round case connector for oil, and look at the old solenoid O-rings when they come out. Our 722.9 pressure control solenoid guide lays out the full test sequence including the vacuum test, and the 722.9 shift solenoid guide covers codes tied to individual shifts and lockup.

Fitment

This set is listed for the Mercedes 722.9 seven-speed automatic and is referenced to part number A2202771098. The listing does not give a year range, and Mercedes revised the 722.9 several times, including the 7G-Tronic Plus update, so compare your old solenoids against the product photo, including the body, tip color and connector, and match the part number printed on them before you install. Send us your year and VIN if you want us to check it. This set is not for the five-speed 722.6 or NAG1; that transmission uses the separate 722.6 pressure control solenoid for 2005-2011. All 7G-Tronic parts we carry are on the 722.6 and 722.9 parts page.

Install notes

• Save the module's fault log first, then drain the fluid and remove the pan and filter to reach the conductor plate and valve body.
• Unclip the old solenoids from the conductor plate one at a time and note each position. Lubricate the new O-rings with clean ATF before seating them.
• While the valve body is out, check the regulator valve bores for wear. If the fluid is burnt and clutches are slipping, a 722.9 overhaul kit is the right next step rather than solenoids alone.
• Refill with ATF meeting the Mercedes approval on your vehicle, MB 236.14 or MB 236.15 depending on build. The 722.9 has no dipstick, so a 722.9 drain and fill kit makes setting the level at temperature far easier.
• Clear codes and reset adaptations with a Mercedes-capable scan tool, then road test so the module relearns each clutch fill.

Is this one solenoid or a full set?

It is a full set of eight 722.9 solenoids, enough to replace every pressure control solenoid on the conductor plate.

What part number does it match?

The set is referenced to Mercedes part number 220 277 10 98 (A2202771098). Compare the number printed on your old solenoids before installing.

Can I replace the solenoids without replacing the conductor plate?

Yes. The solenoids are individually serviceable. The conductor plate and its built-in control module are a separate assembly.

New solenoids did not fix my harsh shifts. What next?

Worn pressure regulator valve bores in the valve body cause the same symptoms. A vacuum test of the valve body bores will show whether that is the problem.

Which fluid does the 722.9 use?

ATF meeting MB 236.14 or MB 236.15, depending on your transmission's build. Use the approval listed for your vehicle and do not mix fluids.

Does it fit the 722.6 or NAG1?

No. This set is for the seven-speed 722.9 only. The five-speed 722.6 and NAG1 use different solenoids.

• 722.9 Pressure Control (EPC) Solenoid Symptoms
• 722.9 Shift Solenoid Symptoms and Replacement
• 722.6 Pressure Control (EPC) Solenoid Symptoms