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Unlocking Acura master key problem

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Unlocking Acura master key problem

Symptom: The retractable master key does not lock in its extended position. This can affect Acura models 2007-2010 MDX, 2007-2010 RDX, 2007-2008 TL, 2009-2010 TL without push-button start, 2009-2010 TSX and 2010 ZDX (without push-button start).

The probable cause: The release button and the collar on the master key become worn after rough use.

The corrective action involves replacing the key case, cutting the new key to match the original, and then re-writing the transponder code into the immobilizer control unit with the HDS.


NOTE: Be sure to use a #0 Phillips screwdriver that is in good condition, and apply enough downforce when removing the screw to avoid screw damage.

1. Using a #0 Phillips screwdriver, remove the screw from the key case. Remove the cover and the key transmitter.

2. Follow the Decode and Copy instructions on the Matrix X key cutter to cut a new key with the new key case. This allows you to use the original key without needing the key code.

3. Assemble the cover and the transmitter onto the new key case and install the screw.

4. To add a key with the HDS, you’ll need: the new master key; the first password (this five-character code is available on the iN. Go to SERVICE, select VEHICLE information from the left column, then select IMMOBILIZER CODE INQUIRY; HDS with software 2.020.018 or later.

NOTE: Make sure that the market, the date and the time on the HDS setup screen are correct. Select the F12 key in the upper right corner to obtain the Set-up Details screen. Make sure that market is set to USA. Select the time display in the lower right corner to view the Date/Time Properties pop-up window. Make sure that the date and time are correct. For details, refer to the HDS Set-up instructions listed under Tool Information in ISIS.

5. Connect the HDS to the DLC (date link connector).

6. Insert the customer’s original key (now without the keyless transmitter) into the ignition switch, and turn the switch to ON. Turn on the HDS.

7. At the screen prompts, enter the VIN and the odometer reading, then verify the correct date and time.

8. From the system Selection screen, select IMMOBI.

9. From the Immobilizer Test Mode screen, select Immobilizer Setup.

10. From the Immobilizer Setup screen, select Add and Delete Keys.

11. From the Add and Delete Keys screen, select Add 1 Key.

12. From the Add 1 Key screen, select Begin to Add 1 Key. NOTE: If there are six keys already in memory, you’ll need to stop and do Delete or Add Multiple Keys, but that requires all of the customer’s keys. Any key not present will no longer start the engine.

13. From the first password screen, enter the first password, then follow the screen prompts. When you are finished, turn the ignition switch to LOCK (0), then turn off and disconnect the HDS.


KEY CASE (does not include transmitter or cover)

APPLICATION                                                             PART NUMBER

2007-2009 MDX – Driver 1                                        35121-STX-305

2007-2009 MDX – Driver 2                                        35121-STX-306

2010 MDX – Driver 1                                                   35120-STX-305

2010 MDX – Driver 2                                                   35120-STX-306

2007 RDX                                                                     35120-STK-305

2008-2010 RDX – Driver 1                                        35121-STX-305

2008-2010 RDX – Driver 2                                         35121-STX-306

2007-2008 TL – Driver 1                                             35120-SEP-305

2007-2008 TL – Driver 2                                             35120-SEP-306

2009-2010 TL (w/0 push button start) – Driver 1   35120-TK4-305

2009-2010 TL (w/o push button start) – Driver 2   35120-TK4-306

2009-2010 TSX – Driver 1                                           35120-TL0-307

2009-2010 TSX – Driver 2                                            35120-TL0-308

2010 ZDX (w/o push button start) – Driver 1             35120-TK4-305

2010 ZDX (w/o push button start) – Driver 2             35120-TK4-306

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