This procedure covers the removal and replacement of the Transmission Control Module (TCM) on a 2016-2024 Hyundai Tucson with the 2.5L I4 AWD powertrain.

Warnings

Tools required

Parts

• Transmission Control Module (TCM) × 1 — Use OEM specification
• TCM mounting bolts (if damaged) × 2 — Use OEM specification

Preparation

1. Ensure vehicle is parked on level ground with parking brake applied
2. Turn ignition off and remove key from vehicle
3. Open hood and secure with prop rod
4. Disconnect negative battery terminal and wait 3 minutes for system capacitors to discharge
5. Locate TCM on driver side of transmission bell housing or mounted to transmission case

Procedure

1. 1

   Access the TCM
   Remove the engine undercover if equipped using 10mm socket. The TCM is typically mounted on the side of the transmission case, accessible from underneath the vehicle on AWD models. You may need to raise the vehicle for better access.
2. 2

   Identify TCM connectors
   Locate the TCM electrical connectors. The 2.5L AWD Tucson typically has two large multi-pin connectors and possibly hydraulic pressure sensor connections integrated into or near the TCM housing. Note the orientation and connector colors for reassembly.
3. 3

   Disconnect electrical connectors
   Press the locking tabs on each electrical connector and carefully pull straight away from the TCM. Do not rock or twist connectors excessively. Use a small flat blade screwdriver to release stubborn locking tabs if necessary. Place shop towels beneath connectors to catch any residual ATF.
4. 4

   Remove TCM mounting bolts
   Remove the TCM mounting bolts using a 12mm socket. There are typically 2-3 bolts securing the module to the transmission case. Keep bolts organized for reinstallation.
   Torque spec

   Mounting Bolts61 Nm (45 lb-ft)
5. 5

   Remove TCM from transmission
   Carefully pull the TCM straight away from the transmission housing. The module may have O-rings or seals that create resistance. If equipped with internal hydraulic connections, expect a small amount of ATF to drain (typically 2-4 oz). Have shop towels ready and allow fluid to drain into a pan.
6. 6

   Inspect mounting surface and seals
   Examine the TCM mounting surface on the transmission case for damage or debris. Inspect O-rings or gasket seals on the old TCM. Clean the mounting surface with a clean shop towel if any dirt or old seal material is present. Do not allow debris to enter the transmission.
7. 7

   Prepare new TCM
   Remove the new TCM from packaging. If the new module includes new O-rings or seals, install them onto the TCM. Lightly lubricate O-rings with clean ATF to ease installation and prevent seal damage. Verify the new TCM part number matches the old unit.
8. 8

   Install new TCM
   Align the new TCM with the mounting holes and any guide pins on the transmission case. Press the module firmly into place, ensuring O-rings seat properly. The module should sit flush against the transmission housing.
9. 9

   Install mounting bolts
   Install the TCM mounting bolts and tighten by hand initially to ensure proper thread engagement. Torque bolts to specification in a criss-cross pattern if multiple bolts are present. Use 20 lb-ft (27 Nm) specification for standard TCM mounting bolts.
   Torque spec

   Mounting Bolts61 Nm (45 lb-ft)
10. 10

    Reconnect electrical connectors
    Reconnect each electrical connector to the TCM, ensuring they click firmly into place and locking tabs fully engage. Gently tug on each connector to verify it is secured. Match connector colors and positions noted during removal.
11. 11

    Reinstall undercover
    If the engine undercover was removed, reinstall it and secure with all fasteners. Ensure all clips and bolts are properly seated.
12. 12

    Reconnect battery and perform initial checks
    Reconnect the negative battery terminal. Do not start the vehicle yet. Turn the ignition to ON position (do not start engine) and verify the instrument cluster illuminates normally. Check for any immediate warning lights or unusual behavior.

Reassembly

1. Verify all electrical connectors are fully seated and locked
2. Ensure no tools or parts were left in the engine bay or under the vehicle
3. Check transmission fluid level is at proper mark on dipstick (if equipped) or through fill plug procedure

Verification

• The new TCM MUST be programmed using a Hyundai GDS or compatible factory-level scan tool by a dealer or qualified technician
• After programming, verify all transmission functions operate normally in Park, Reverse, Neutral, and Drive
• Test drive the vehicle and confirm smooth shifting through all gears with no warning lights
• Verify no ATF leaks are present around the TCM mounting area after test drive
• Use a scan tool to confirm no transmission-related diagnostic trouble codes are present
• Check that shift indicator in instrument cluster matches actual gear position

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