Ignition Switch

This procedure covers the removal and replacement of the ignition switch assembly on the 2007-2013 Mercedes-Benz S65 AMG, including steering column cover removal and electrical disconnection.

Warnings

Tools required

Parts

• Ignition switch assembly × 1 — Use OEM specification
• Steering column cover clips (if damaged) × 1 — Use OEM specification

Preparation

1. Park vehicle on level surface and ensure wheels are straight
2. Set parking brake firmly
3. Disconnect battery negative terminal and wait minimum 15 minutes for capacitor discharge
4. Remove key fob from vehicle and place at least 10 feet away
5. Adjust steering column to lowest and furthest forward position for access
6. Document or photograph electrical connector positions before disconnection

Procedure

1. 1

   Remove lower steering column covers
   Remove the lower knee bolster panel by pulling firmly at the lower edge to release clips. Remove the T20 Torx screws securing the lower steering column cover (typically 3-4 screws). Carefully separate the lower cover from upper cover, working around the steering column shaft. Note the position of any cable routing clips attached to the cover.
   Torque spec

   Cover Screws15 Nm (11 lb-ft)
2. 2

   Remove upper steering column cover
   With lower cover removed, locate and remove the T20 Torx screws securing the upper steering column cover (typically 2-3 screws). Gently lift the upper cover away from the column, being careful not to damage the wiring harness for the multifunction switch. Set covers aside in a clean area.
   Torque spec

   Cover Screws15 Nm (11 lb-ft)
3. 3

   Disconnect ignition switch electrical connectors
   Locate the ignition switch electrical connector on the right side of the steering column. Press the locking tab and carefully disconnect the main connector. If equipped with additional security connectors, disconnect those as well. On S65 AMG models, there may be up to three separate connectors including Keyless-Go module connections.
   ⚠Do not force connectors. Each has a specific locking mechanism that must be released before pulling.
4. 4

   Remove ignition switch mounting fasteners
   Locate the ignition switch mounting screws (typically two T25 Torx screws) on the side of the ignition lock housing. Remove these screws completely. On some S-Class models, there may be a retaining bracket secured with an additional screw that must be removed first.
   Torque spec

   Switch Mounting Screws5 Nm (4 lb-ft)

   Bracket Bolts27 Nm (20 lb-ft)
5. 5

   Remove ignition switch assembly
   With mounting screws removed, carefully slide the ignition switch assembly away from the steering column lock cylinder housing. The switch may require slight rotation or wiggling to clear internal alignment pins. Pull the switch straight back once clear of the housing. Inspect the mounting area for any debris or damage.
   ℹ️The ignition switch is separate from the lock cylinder. Do not attempt to remove the lock cylinder unless specifically required.
6. 6

   Prepare new ignition switch
   Compare the old and new ignition switches to verify correct replacement part. Check that all electrical connector pins are straight and undamaged on the new switch. If the new switch came with a protective cap over the connector, remove it now. Ensure the alignment pins on the back of the switch are present and undamaged.
   ⚠Do not touch electrical contacts with bare hands. Use clean gloves to prevent oil contamination.
7. 7

   Install new ignition switch
   Align the new ignition switch with the steering column lock housing, ensuring alignment pins engage properly. Slide the switch into position until it seats flush against the housing. The switch should slide in smoothly without excessive force. Verify the switch is fully seated before proceeding.
   ⚠Misalignment of the switch can damage internal components. Ensure proper pin engagement before applying pressure.
8. 8

   Secure ignition switch mounting fasteners
   Install the ignition switch mounting screws and tighten to specification using a torque wrench. If a retaining bracket was removed, install and torque bracket bolts first, then switch mounting screws. Ensure the switch does not shift during tightening.
   Torque spec

   Switch Mounting Screws5 Nm (4 lb-ft)

   Bracket Bolts27 Nm (20 lb-ft)
9. 9

   Reconnect electrical connectors
   Reconnect all electrical connectors to the ignition switch in the reverse order of removal. Ensure each connector clicks firmly into place and locking tabs are fully engaged. Verify no pins are bent and connectors are seated completely. Route wiring to match original configuration and secure any cable clips.
   ⚠Partially connected or loose connectors will cause starting issues and may set fault codes.
10. 10

    Reinstall steering column covers
    Position the upper steering column cover over the column and install the cover screws to specification. Install the lower steering column cover, ensuring all alignment tabs engage properly, then install and torque the screws. Verify all cover edges are flush and no gaps exist. Reinstall the knee bolster panel by pressing firmly until clips engage.
    Torque spec

    Cover Screws15 Nm (11 lb-ft)
11. 11

    Reconnect battery and perform system initialization
    Reconnect the battery negative terminal. The vehicle may require ignition switch initialization or coding using Mercedes XENTRY diagnostic system. Cycle the ignition from OFF to ON position three times without starting the engine to allow the Electronic Ignition Switch (EIS) module to recognize the new switch. Check for any warning lights on the instrument cluster.
    ℹ️S65 AMG models typically require dealer-level programming for ignition switch replacement due to anti-theft system integration.

Reassembly

1. Ensure all steering column covers are properly secured with no rattles or loose panels
2. Verify all electrical connectors are fully seated and locked
3. Confirm no tools or parts were left in the steering column area
4. Check that steering column adjustment functions work properly after reassembly

Verification

• Turn ignition to ON position - all dashboard lights should illuminate normally
• Verify steering lock releases when ignition is turned on
• Test engine starting function - engine should crank and start normally
• Verify Keyless-Go function operates correctly (if equipped)
• Check that ignition can be turned to all positions: LOCK, ACC, ON, and START
• Confirm no warning lights related to ignition system or EIS remain illuminated
• Scan for fault codes using diagnostic system and clear any memory codes from the old switch
• Test that key can be removed only when in LOCK position with transmission in Park

Related trouble codes on this vehicle

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