Quick Reference Guide: Pontiac Grand Prix

Dec. 1, 2008
The transponder programming for the Grand Prix is a little odd, so you need to pay particular attention to the section in this article on programming.
The latest version of the Pontiac Grand Prix (Photo 1) was introduced in 2004, as one of the early GM vehicles equipped with the Z-Keyway. From 2004 until 2007, all of these vehicles were equipped with Ortech locks using the Z-Keyway and the PK3 transponder system. In the 2008 model year the locks remained essentially the same, but the transponder system changed to the “Circle Plus” system. Another oddity about the Grand Prix is the deck lock. Only the 2004 Grand Prix was equipped with a trunk lock. Beginning with the 2005 model year, the trunk lock was eliminated. The transponder programming for the Grand Prix is also a little odd, and you need to pay particular attention to the section in this article on programming.

Use the long end of the Tech-Train 1008 tool to unlock the Grand Prix. The fit of the weatherstripping at the base of the window is so tight that it is actually easier to insert the tool without a wedge. I use a plastic shim to hold the lower layers of the weatherstripping out of the way as I insert the tool. The shim is inserted at the extreme rear corner of the door.

Before inserting the tool into the door, I place the tool against the outside of the door and measure the distance from the top of the weatherstripping to the top of the trim strip on the door. This is the depth that I want to lower the tool into the door. You can either put a mark on the shaft of your tool, or hold your fingers on the tool at the depth you need to go as you insert the tool.

Gently work the long end of the tool between the shim and the glass. Once the tip of the tool is free inside the door, lower it to the point that you measured off earlier. While keeping the shaft of the tool vertical, rotate the tip of the tool that is inside the door as far as it will go toward the inside of the vehicle. When the tool stops, it should be against the side of the vertical linkage rod.

While watching the inside lock button for movement, pull up on the tool to unlock the door. If the tool slips off, re-position the tool and try again while twisting the tool so that the tip of the tool is pressed harder against the linkage rod.

With the door panel removed, we can see how the tool contacts the linkage rod. (See Photo 4) If you have lowered the tool to the proper depth inside the door, the hooked end of the tool should be held firmly against the linkage rod. Pulling up on the tool while you hold pressure against the linkage rod will lift the linkage and unlock the door.

Only the driver’s side door is equipped with a lock, and it is mounted in a traditional GM handle assembly. Removing the lock from the door will require you to remove the inner door panel and then loosen or remove the outside door handle so that you can release the spring-wire clip that holds the lock in place.

The door panel on the Grand Prix is fairly simple to remove. Two 10mm bolts are concealed in the armrest, a series of upholstery clips are around the edge of the door and three small pieces of trim must be removed

Begin by carefully prying the plastic insert free of the armrest, to expose the two 10mm bolts that secure the door panel to the door. After these bolts have been removed, the only thing holding the panel on will be the upholstery clips.

The small triangular trim piece at the forward corner of the door is held in place by two upholstery clips. With a little gentle prying, this piece will pop off in your hand.
The circular trim around the inside door handle is held in place with two upholstery clips, located at the top and bottom of the trim. In photo 5, I am using a wooden wedge to carefully pry the edge of the trim away from the panel.

The two upholstery clips on the back of the handle trim have a surprisingly strong grip, so make sure that you do not scratch the trim or the door panel as you remove the handle trim.

Two slots on the lower edge of the door panel are designed for you to insert a clip removing tool. Carefully pry out along the lower edge of the panel to disconnect the upholstery clips one by one. After all of the clips have been released, the top edge of the panel can be pulled up to release the door panel from the door.

All of the wiring that is attached to the door panel is routed through one central connector. Pulling up on the green handle on top of the connector will unlock the connector and push the two portions apart. After the connector has been released, the door panel will be free of the door.

The green handle that is used to disengage the two portions of the connector. This portion of the wiring harness will stay with the door.

The opposite side of the connector that is attached to the door panel. When you reattach the two portions of the connector, do not bend any of the pins, and that the green handle snaps fully into the locked position.

Carefully peel back the clear plastic moisture barrier so that you can reach inside the door cavity. Do not cut or tear this plastic since it serves the very important function of keeping water out of the electronics and other sensitive materials that are attached to the door panel.

The outside handle assembly is secured to the door with two 10mm bolts. Two holes through the inner skin of the door give you direct access to each bolt.

The second access hole is the same hole that the vertical linkage rod passes through. You must remove the rubber grommet before you can access the bolt. Be sure to properly replace the grommet when you reassemble the door, since it also acts as a moisture barrier and a guide for the linkage rod.

Before you can free the handle assembly from the door, you must disconnect the linkage rod from the lock pawl.

Once the two bolts have been removed, and the linkage rod has been disconnected, the handle will pull out of the door. The handle linkage is still connected, so the handle will not pull out very far, but you only need to pull it out this far to remove the spring-wire clip that holds the lock in place.

Once the wire retainer has been pulled back slightly, the lock will be free to slide out from the back of the housing. As soon as the lock is out, you can push the wire retainer back into place. When you slide the lock back into the housing, the ramps on the side of the lock will allow the lock to snap securely back into place.

Once the lock has been removed from the housing, it can be disassembled. The face cap snaps on and off and can be reused. The shutter assembly should stay in place on the front of the lock, but in this case it came off along with the face cap.

If you have to take the shutter assembly apart, watch out for flying springs and parts. I don’t recommend removing the shutter assembly.

There is also a spring-ball detent located at the rear of the lock housing. As you remove the lock plug from the housing, do not lose the spring or the ball. As you reassemble the lock, use a small tool to hold the ball in the compressed position as you slide the plug into place.

The glove box lock, if equipped, can be removed easily by removing the two screws that hold it in place. Once removed, you can get cuts 7 – 10 from the glove box lock.

The lock plug is held in place by a retainer located near the front of the lock plug. A poke-hole in the side of the housing gives you access to the retainer once you have turned the plug, either with the key or by picking, to the locked position.

With the plug removed from the housing, it is easy to sight read the depths of the four wafers. Or, since each wafer is stamped with the depth, you can remove the wafers to decode the lock.

Only the 2004 model year Grand Prix is equipped with a trunk lock, and it has a face cap that is not reusable.

Inside the trunk, there is no problem gaining access to the lock. The lock is secured by a clip that can be easily removed. If you have a trunk lock to work with, you will be able to obtain cuts 3 – 10 from the trunk lock.

The in-dash ignition lock is difficult to remove unless you have a key, or you can pick the lock. If your goal is to generate a key for the vehicle, you would be better off to obtain cuts 3 - 10 from the door or trunk lock and then progression the remaining two cuts that are found only in the ignition. However, if you need to service the ignition lock and can turn the lock, it is easy to remove. First, carefully pry the trim ring free of the lock. It is held in place by four sets of plastic clips that snap over the four posts on the front of the lock.

Directly below the ignition lock is a rubber pad that protects the trim from hanging keys. Carefully pry this pad free of the trim and you will find one screw that secures the center stack trim to the dash. Removing the screw will allow you to release the trim.

After the screw has been removed, the only thing holding the trim in place is a series of upholstery clips around the edge of the trim. Carefully pry the trim free of the dash, making sure not to scratch the trim or the dash.
The trim does not have to be completely removed in order to remove the lock. Rotate the trim just far enough to expose the lock. At the 5 o’clock position, you will find an opening into the dash. Look inside with a flashlight to see the lock retainer. To remove the lock, turn it to the “ON” position and depress the retainer with an offset scribe or similar tool. The “ON” position is the second click – the first click is the accessory position and the retainer cannot be depressed in that position.

Once the retainer has been depressed, the lock and the attached transceiver ring will slide out of the housing. The transceiver ring is the heart of the transponder system and is relatively fragile. Avoid prying or twisting the ring –a coil of very fine wire inside the ring acts as an antenna for the transponder system. The ring is intentionally fragile, so that it will be easily damaged in a theft attempt in order to make the vehicle inoperable. The code number will also be stamped on the side of the lock.

The transceiver ring is held in place by a single snap-clip at the top of the lock. To remove the transceiver ring, gently lift the snap-clip and slide the transceiver ring off of the lock.

Looking at the rear of the lock, you will see the three-pin socket on the back of the transceiver ring that plugs into a matching plug in the ignition housing. You can also see the retainer pin that holds the lock plug in place. To remove the lock plug, depress the retainer pin with a pick or other small tool and then rotate the lock until plug slides out of the housing. The lock has to be rotated until the timing lug aligns with the sidebar slot in the lock housing.

he lock plug has been removed and you can see the retainer pin and the spring that is normally located below the pin. As you remove the lock plug, make sure that you do not lose the pin or the spring. As you remove the plug from the housing, the spring will attempt to shoot the retainer pin across the room. I usually wrap a rag around the entire lock as I disassemble it to trap any flying parts. I have also removed the grease from the lock so that you could see the details better.

The timing lug must be aligned with the sidebar slot in the lock housing in order for the plug to come out of the housing.

Distinctive Ortech tumblers can be used in both the sidebar ignition and the non-sidebar door and trunk locks. Once again, each tumbler is stamped with the depth. The Grand Prix uses the O5000 – O6999 code series. Even though there are five depths listed, the number five depth is not used in any code in the system.

Programming replacement keys for a Grand Prix made between 2004 and 2007 can be tricky. Some Grand Prixs simply cannot be programmed with on-board methods. The only way those vehicles can be programmed is with a GM TECH-II device that is loaded with the TIS-2000 software. Fortunately, those vehicles are few and far between in the U.S. Unfortunately, the only way to identify them is to try and fail to program a key into it.

The vast majority of U.S. Grand Prixs can be programmed with the standard PK3 on-board programming procedure, but with one catch. DO NOT insert a key into the ignition that does not have a transponder, unless the battery is disconnected! Any time a key is inserted into the ignition far enough to activate the key buzzer, the transceiver ring will be activated. If the transceiver ring does not detect a transponder, it will assume that there is a theft attempt in progress and initiate a trouble code in the computer. Without the proper equipment, this trouble code may be impossible to clear.

There are two solutions to this problem if you are generating a key for the vehicle. The easiest is to simply disconnect the battery until you have made a mechanical key that will turn the ignition, and then reconnect the battery when you are ready to program the key. The other option is to hold a blank transponder key next to the ignition lock while you perform the progression for the two cuts that are found only in the ignition. This way the computer will detect a transponder and it should not trigger a theft code.

If you encounter a vehicle that has been locked down due to someone inserting a non-transponder key into the ignition, you may be able to clear the problem with the following procedure:

Disconnect the battery for a minimum of ten minutes

Insert your transponder key with the correct cuts into the ignition, but do not turn the ignition on

Reconnect the battery with the key in the ignition

Turn the ignition key on for three cycles of ten minutes and forty-five seconds each.

If this does not solve the problem, you will probably have to refer the vehicle to the dealer.

Under normal circumstances, you can program a replacement key with three ten-minute cycles, the same as any other PK3 vehicle. While programming the vehicle, you will have to watch the “Driver Information Display” since the Grand Prix does not have a stand-alone security light.

While programming the vehicle, you will see the message “Starting Disabled Due To Theft System” on the Driver Information Display. When the programming is successful, a message similar to Photo 21 will appear.

Programming a duplicate key into the Grand Prix is easy as long as you have at least one working key. Simply start the car with the working key and then turn it off. Within ten seconds of removing the working key, insert the new key and start the car. The Grand Prix can be programmed for a maximum of ten keys, but since the PK3 blanks can be cloned, it is possible to have an unlimited number of keys.

In the 2008 model year, the Grand Prix went to the “Circle Plus” system. This makes it very important for you to check the tenth digit of the VIN for the model year, so that you can be sure what year vehicle you are working on.