Replace the overdrive solenoid in the automatic transmission to restore proper shifting and overdrive function.

Warnings

Tools required

Parts

• Overdrive solenoid × 1 — Use OEM specification
• Transmission pan gasket × 1 — Use OEM specification
• Transmission filter (if applicable) × 1 — Use OEM specification
• Transmission drain plug crush washer × 1 — Use OEM specification

Fluids

• Kia SP-IV-M ATF — 4.5 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. If engine is warm, allow transmission to cool for at least 30 minutes
3. Raise and support vehicle securely on jack stands
4. Locate transmission pan and overdrive solenoid access point on valve body
5. Position drain pan under transmission pan
6. Have replacement parts and fluids ready before disassembly

Procedure

1. 1

   Drain transmission fluid
   Remove the transmission drain plug using a 14mm socket and allow fluid to drain completely into drain pan. Once drained, install new crush washer on drain plug and reinstall drain plug.
   Torque spec

   Transmission Drain Plug30 Nm (22 lb-ft)
2. 2

   Remove transmission pan
   Remove all transmission pan bolts in a criss-cross pattern starting from the center and working outward. Carefully lower the pan, being aware additional fluid will spill out. Remove the pan and gasket completely.
   ⚠Approximately 1-2 quarts of fluid will remain in pan. Have drain pan positioned to catch spillage.
   Torque spec

   Pan Bolts15 Nm (11 lb-ft)
3. 3

   Clean transmission pan and inspect
   Clean the transmission pan thoroughly with solvent and inspect for metal shavings or debris. Excessive metal debris indicates internal transmission wear. Clean the pan mating surface on the transmission case using a plastic scraper, being careful not to gouge the aluminum surface.
4. 4

   Remove transmission filter if equipped
   If your transmission has a serviceable filter, remove the filter mounting bolts and pull filter straight down. Some 2015 Forte models use an internal filter that is not serviceable during this procedure. Inspect the filter mounting area and clean any residue.
   ℹ️The 6-speed automatic in 2015 Forte may have a permanent internal filter. Only replace if accessible.
5. 5

   Locate overdrive solenoid on valve body
   With the pan removed, identify the overdrive solenoid on the valve body. It is typically located on the driver's side of the valve body and has an electrical connector. The solenoid is secured by one or two bolts.
6. 6

   Disconnect solenoid electrical connector
   Carefully disconnect the electrical connector from the overdrive solenoid. Note the connector orientation for reinstallation. Inspect connector pins for corrosion or damage.
7. 7

   Remove overdrive solenoid
   Remove the solenoid mounting bolts using a 10mm socket. Carefully pull the solenoid straight out from the valve body. Note the position of any O-rings or seals. Inspect the valve body bore for debris or scoring.
   ⚠Do not allow debris to enter the valve body. Keep area clean during solenoid removal.
   Torque spec

   Sensor Bolts10 Nm (8 lb-ft)
8. 8

   Install new overdrive solenoid
   Lubricate new solenoid O-rings with clean ATF. Insert the new solenoid straight into the valve body bore, ensuring proper alignment. Install and hand-tighten mounting bolts, then torque to specification.
   Torque spec

   Sensor Bolts10 Nm (8 lb-ft)
9. 9

   Reconnect electrical connector
   Reconnect the electrical connector to the new overdrive solenoid, ensuring it clicks securely into place. Verify connector is fully seated.
10. 10

    Install new filter if applicable
    If filter was removed, install new transmission filter. Ensure filter seats properly and tighten mounting bolts to specification.
    Torque spec

    Sensor Bolts10 Nm (8 lb-ft)
11. 11

    Install new pan gasket and transmission pan
    Position new gasket on transmission pan or case (depending on gasket design). Align transmission pan and install all bolts hand-tight. Tighten bolts in criss-cross pattern to specification, starting from center and working outward.
    ⚠Do not overtighten pan bolts as this can warp the pan and cause leaks.
    Torque spec

    Pan Bolts15 Nm (11 lb-ft)
12. 12

    Refill transmission with ATF
    Lower vehicle to ground. Remove transmission dipstick (if equipped) or remove fill plug on side of transmission case. Using a transmission funnel, add approximately 4.5 quarts of Kia SP-IV-M ATF. Start engine and allow to idle in Park.
    ℹ️Some 2015 Forte models do not have a dipstick and require fill through check plug. Refer to fill procedure in owner's manual.
13. 13

    Check fluid level and cycle gears
    With engine idling and parking brake engaged, shift through all gear positions (P-R-N-D-L) pausing 2-3 seconds in each. Return to Park. Check fluid level on dipstick or at check plug opening. Add fluid as needed to bring to proper level on dipstick at operating temperature.

Reassembly

1. Ensure all electrical connectors are fully seated and secured
2. Verify no tools or rags were left in work area before lowering vehicle
3. Double-check transmission pan bolts are torqued properly in criss-cross pattern
4. Confirm drain plug is tight with new crush washer installed

Verification

• Start engine and verify no fluid leaks from transmission pan or drain plug
• Test drive vehicle and confirm all gears engage properly
• Verify overdrive function is restored (typically engages above 45 mph in Drive)
• Check for proper shifting through all gears under light and moderate acceleration
• Recheck fluid level after test drive at operating temperature
• Clear any diagnostic trouble codes using scan tool and verify no new codes set

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