Shift Solenoids - All

This procedure covers the removal and replacement of all shift solenoids in the ZF 6HP26 automatic transmission used in the 2009 Aston Martin DB9, requiring transmission pan removal and ATF fluid replacement.

Warnings

Tools required

Parts

• Shift solenoid valve assembly (Solenoid A) × 1 — Use OEM specification
• Shift solenoid valve assembly (Solenoid B) × 1 — Use OEM specification
• Shift solenoid valve assembly (Solenoid C) × 1 — Use OEM specification
• Shift solenoid valve assembly (Solenoid D) × 1 — Use OEM specification
• Shift solenoid valve assembly (Solenoid E) × 1 — Use OEM specification
• Transmission pan gasket × 1 — Use OEM specification
• Transmission drain plug crush washer × 1 — Use OEM specification
• Mechatronic valve body O-rings (if applicable) × 1 — Use OEM specification

Fluids

• Touchtronic 6-speed ZF ATF — 9.5 qt

Preparation

1. Ensure the vehicle has been sitting long enough for transmission fluid to cool to ambient temperature (minimum 2 hours after operation).
2. Park the vehicle on a level surface and engage the parking brake.
3. Raise the vehicle on a lift or secure it on jack stands rated for the vehicle weight, ensuring adequate working clearance underneath.
4. Remove the undertray panels to access the transmission pan. These are typically secured with Torx fasteners around the perimeter.
5. Place a large drain pan beneath the transmission oil pan.
6. Have all replacement solenoids, gaskets, and fluids ready before beginning disassembly.

Procedure

1. 1

   Drain transmission fluid
   Locate the transmission drain plug on the bottom of the transmission pan. Place the drain pan directly beneath the plug. Using the appropriate socket, slowly loosen and remove the drain plug, allowing the ATF to drain completely. This will take several minutes. Once drained, inspect the drain plug and crush washer. Discard the old crush washer and clean the drain plug threads.
2. 2

   Remove transmission pan bolts
   Locate all transmission pan bolts around the perimeter of the pan. The transmission pan is secured by a number of perimeter bolts (verify exact count against Aston Martin/ZF service documentation). Beginning at one corner, loosen all bolts in a criss-cross pattern by 2-3 turns each to relieve sealing pressure evenly. Beginning at one corner, loosen all bolts in a criss-cross pattern by 2-3 turns each to relieve sealing pressure evenly. Once all bolts are loosened, remove them completely and set aside. Note: Some residual fluid will remain in the pan. Note: The ZF 6HP26 transmission pan is secured by a perimeter pattern of bolts; verify the exact bolt count in Aston Martin/ZF service documentation before removal.
3. 3

   Lower and clean transmission pan
   Carefully lower the transmission pan, keeping it level to avoid spilling residual fluid. Once clear, pour any remaining fluid into the drain pan. Remove and discard the old gasket from both the pan and transmission housing mating surfaces. Clean both surfaces thoroughly with a plastic scraper and lint-free towels. Remove all old gasket material and ensure surfaces are clean and dry. Inspect the pan for metal debris or clutch material (indicates other transmission issues).
4. 4

   Access mechatronic valve body
   With the pan removed, the mechatronic valve body is now visible on the bottom of the transmission. The valve body houses all shift solenoids in an integrated unit. Identify the solenoid locations: they are mounted on the valve body with individual electrical connectors. Take photos of the wiring harness routing and connector positions for reference during reassembly.
5. 5

   Disconnect solenoid electrical connectors
   Locate the shift solenoid electrical connectors on the valve body/mechatronic unit. Verify the exact number and type of solenoids against Aston Martin/ZF service documentation, as several may be integrated into the mechatronic module rather than individually removable. These connectors have locking tabs that must be gently depressed before pulling. Starting with Solenoid A, press the locking tab and gently pull the connector straight away from the solenoid. Repeat for Solenoids B, C, D, and E. Do not twist or bend the connectors during removal. Inspect each connector for corrosion or contamination; only clean with electronics-safe contact cleaner if corrosion is present, and allow to dry fully before reassembly. Note: Identify the shift solenoid locations on the mechatronic valve body. Consult Aston Martin/ZF documentation for the exact number and arrangement of solenoids, as the 6HP26 integrates its solenoids into the mechatronic module rather than as individually connectored units.
6. 6

   Remove Solenoid A
   Solenoid A retention method varies — verify whether it is secured by a retainer plate, clip, or bolt per the ZF/Aston Martin service documentation before attempting removal. Verify the solenoid retention method against ZF/Aston Martin documentation — on the 6HP26 the solenoids are integrated into the mechatronic module and may not be individually bolt-retained. Do not attempt to extract individual solenoids from bores until the correct documented service method (individual solenoid vs. full mechatronic replacement) is confirmed. Some resistance is normal due to the O-ring seal. Inspect the O-ring that remains in the valve body bore or on the solenoid. If damaged or worn, replace with new O-ring from the solenoid kit. Clean the bore with lint-free towels. Note: Determine the solenoid retention method from ZF/Aston Martin documentation. On the 6HP26 mechatronic unit solenoids are typically held by a retaining plate or clip rather than individual Torx bolts; remove the correct retainer before extracting the solenoid.
7. 7

   Remove Solenoid B
   Only repeat an individual-solenoid removal process if the service documentation confirms Solenoid B is individually serviceable; otherwise the solenoids are replaced as part of the mechatronic assembly. Verify before proceeding. Inspect the O-ring seal and valve body bore. Clean the bore thoroughly with a lint-free towel. Check for any debris or metal particles.
8. 8

   Remove Solenoid C
   Remove Solenoid C using the same procedure: remove the Torx retaining bolt and extract the solenoid. Inspect and clean the bore. Ensure no debris enters the valve body during removal.
9. 9

   Remove Solenoids D and E
   If the documentation confirms individually serviceable solenoids, remove any remaining solenoids per the documented procedure, inspect O-rings, and clean each bore. Verify the exact number and arrangement of solenoids in the 6HP26 mechatronic unit against ZF/Aston Martin documentation — do not assume exactly five discrete bolt-in solenoids. Wipe the entire exposed valve body surface with clean, lint-free towels.
10. 10

    Install new Solenoid A
    Unpack the new Solenoid A and verify it matches the original. Check that the O-ring is properly seated in the solenoid groove. Lightly lubricate the O-ring with clean ATF. Align the solenoid with its bore and insert straight in, applying gentle but firm pressure until fully seated. If the solenoid is bolt-retained, tighten to the torque specified in the official ZF/Aston Martin service documentation (verify — do not assume). If the solenoid uses a retainer plate or clip, follow the documented retention procedure instead. Note: Install the solenoid retainer and tighten to the ZF/Aston Martin specified torque. Do not rely on a generic value; verify the exact specification in the service documentation before final tightening.
11. 11

    Install new Solenoids B, C, D, and E
    Repeat the installation process for each remaining solenoid. For each solenoid: verify correct part, check O-ring seating, lubricate O-ring with ATF, insert straight into bore until seated, and install retaining bolt to specification. Ensure each solenoid is fully seated before tightening the retaining bolt. Double-check that you have installed all five solenoids in their correct positions.
12. 12

    Reconnect solenoid electrical connectors
    Reconnect each solenoid electrical connector, starting with Solenoid A and working through E. Push each connector straight onto its solenoid terminal until you hear or feel the locking tab engage. Gently tug on each connector to verify it is securely locked. Verify all connectors are fully seated and properly routed away from moving components.
13. 13

    Install new pan gasket and reinstall pan
    Position the new transmission pan gasket on the transmission housing mating surface. Ensure it is properly aligned with all bolt holes. Carefully lift the clean transmission pan into position, aligning it with the gasket and bolt holes. Start all pan bolts by hand, threading them 2-3 turns each to hold the pan in position. Once all bolts are started, tighten them in a criss-cross pattern to the specified torque.
14. 14

    Install drain plug and refill transmission
    Install the new crush washer on the drain plug. Thread the drain plug into the transmission pan by hand, then tighten to the specified torque. Locate the transmission fill/level plug on the underside of the transmission (the 6HP26 is filled and leveled via a plug on the fluid pan, not from above and not via a dipstick). Using a fluid pump or funnel with extension, add the specified quantity of ZF ATF. Fill slowly to avoid overfilling. Add the fluid quantity appropriate for a pan-drop service (less than full dry-fill capacity, as the torque converter and cooler retain fluid) — verify the exact refill quantity against service documentation. Note: this transmission uses a fill/level plug with a temperature-dependent level procedure, not a dipstick. Note: Refill the transmission using the ZF level-plug fill procedure. The 6HP26 uses a sealed fill with an overflow/level plug (not a dipstick); add fluid until it runs out of the level plug at the specified fluid temperature. A pan drain-and-refill typically takes well under the full dry-fill capacity — verify exact quantity against service data.
15. 15

    Verify fluid level and test system
    With the transmission filled, start the engine and allow it to idle. With the parking brake engaged, shift through all gear positions (P-R-N-D-Manual mode), pausing 2-3 seconds in each position. Return to Park. With the engine running and the transmission fluid within the specified level-check temperature window per ZF/Aston Martin documentation (this is a narrow window, not full operating temp), check the fluid level using the fill/level plug procedure specified for this transmission (no dipstick is fitted). Add fluid as needed to achieve the correct level. Reinstall any undertray panels removed during preparation. Note: With the engine running, set the transmission fluid level at the ZF-specified fluid temperature (typically 30-50°C, monitored via diagnostic tool) using the level/overflow plug procedure — this transmission does not use a dipstick. Confirm the exact temperature window in service documentation.

Reassembly

1. Reinstall all undertray panels removed during preparation, ensuring all Torx fasteners are tightened securely.
2. Lower the vehicle from the lift or jack stands.
3. Test drive the vehicle to verify proper shift operation. Monitor for any shift delays, harsh engagements, or abnormal behavior.
4. After the first 50-100 miles of driving, recheck the transmission fluid level and top off if necessary.

Verification

• Verify there are no fluid leaks from the transmission pan gasket or drain plug.
• Confirm all shift solenoid electrical connectors are fully seated and locked.
• Test drive the vehicle and verify smooth shifts in all gears, both automatic and manual modes.
• Scan for diagnostic trouble codes using an OBD-II scanner. Clear any stored codes and verify no new codes appear after test drive.
• Verify transmission fluid level is correct at operating temperature.
• Listen for any abnormal noises from the transmission during operation.

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