Does This Vehicle Have A Transponder?

Sooner or later you will run into a vehicle that either has a transponder system that you didn’t expect or doesn’t have one when you thought it would. The best way of keeping those surprises to a minimum is to pay attention to the details, use...

How can you tell if a vehicle is equipped with a working transponder system? The easiest way is to try to start it with a non-transponder key and see what happens. Unfortunately, what will often happen is that the transponder system will see this as a theft attempt, throw a theft code into the...

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The Pontiac Grand Prix, made from 2004 – 2008, uses a more or less standard GM system except for one very important feature. If you attempt to start one of these vehicles with a non-transponder key, it will usually throw a “theft code” into the computer that will require dealer equipment to clear. If you need to test your mechanical key in the ignition, disconnect the battery before you try the key. Then, before you re-connect the battery, insert your transponder key into the ignition, but don’t turn it on. That way, as soon as the system “wakes up” it will see a transponder key and not throw a theft code.


Nissan Vehicles

As I mentioned earlier, the Nissan Titan has transponders as optional equipment depending on the trim level and options found on the vehicle. Old-fashioned manual wind-up windows are usually a dead give-away that the vehicle is not transponder equipped. This is also true of the Nissan Xterra, made from 2000 – 2004, but most other Nissans that have a transponder system use it as standard equipment. Even though these “entry level” vehicles are not equipped with a transponder system, they are shipped with transponder keys because that is more cost effective than having special keys for the non-transponder vehicles. For this reason, you really can’t be sure about these vehicles until you are on the job.

The first Nissan product to be equipped with transponders was the 1997 Infiniti Q45. In 1999, the Nissan Maxima got essentially the same system. The Nissan Pathfinder got the same system as the Maxima mid-year in the 1999 model year. All three of these vehicles used a proprietary Nissan programming port instead of the OBD port for programming. This means that you MUST have a special cable or adapter in order to program these vehicles with most diagnostic tools. Other than these exceptions, the entire Nissan fleet since 2001 has been transponder equipped.


Toyota Vehicles

Early Toyota transponder systems seem to have been designed for maximum inconvenience for both the owner and the technician. The Engine Control Unit (ECU) that contains the immobilizer system was designed in such a way that if the keys were lost or stolen, the ECU would have to be replaced at a minimum cost of about $1,200. As you can imagine, this did not go over well with Toyota / Lexus owners since initially the ECU replacement was not covered under warranty in a lost key situation.

A few enterprising technicians came up with ways to manually reset the ECU, with a process now known as “re-flashing.” Eventually, Toyota adopted a system that could be reprogrammed without such extreme measures, but they never seemed to be in a hurry to implement it.

The following Toyota and Lexus vehicles have the older system that must be re-flashed if there is no “master key” available.

  • Toyota 4Runner: 1999-2002
  • Toyota Avalon: 1998-2004
  • Toyota Camry: 1998-2002
  • Toyota Highlander: 2001-2003
  • Toyota Land Cruiser: 1999-2002
  • Toyota Prius: 2001-2003
  • Toyota Sequoia: 2003-2007
  • Toyota Sienna: 1998-2003
  • Toyota Solara: 1999-2003
  • Lexus ES Series: 1998-2003
  • Lexus GS Series: 1998-2005
  • Lexus IS Series: 2001-2005
  • Lexus LS Series: 1997-2000
  • Lexus LX Series: 1998-2002
  • Lexus RX Series: 1999-2003
  • Lexus SC Series: 1998-2000

On these systems, new keys could be programmed with a complicated on-board procedure that involved opening and closing doors and / or stepping on the brake or gas pedal in a specific sequence as long as at least one “Master” key was available. The real difference between the “Master” key and the “Valet” key is an electronic difference rather than a mechanical difference. The OEM Valet keys have a charcoal grey rubber head and the OEM master key has a black rubber head. However, over time they all begin to look black, and aftermarket keys can be any color.

The best way to determine if you have a master or a valet key is to insert it into the ignition and observe the security light. When a master key is inserted (it’s not necessary to turn the key), the security light will either not come on at all, or it will go out instantly. When a valet key is inserted into the ignition, the security light will hesitate for just a second before it goes out.


Other Systems

The systems used by Honda, Hyundai, Kia, Mazda and other Asian manufacturers are usually standard equipment on particular models. Your reference materials will usually spell these out in detail. As a general rule, transponder systems are rare on Hyundai and Kia vehicles made before 2006.

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