• 2018

Crime Stopper.

Replacing the brainy system that prevents thievery.

Anti-theft technology has improved drastically, making vehicle theft more and more diffi cult for car thieves. One such technology is the Sentry Key Immobilizer System (SKIS). This system uses an electronically coded ignition key that must be used to start the vehicle. In other words, a copy of the key with the same pattern made at a hardware store could not start the engine and allow it to remain running. The immobilizer system will turn the engine off after 2 seconds.

The brains of this system is the Sentry Key Immobilizer Module, or SKIM (see Figure 1). The SKIS was first used on minivans around 2005. Between 2004 and 2006, some Chrysler Town & Country and Dodge Caravan models had this technology, others did not. This system contains a radio frequency (RF) transceiver and microprocessor. The SKIM transmits and receives RF signals through a tuned antenna enclosed within a molded plastic ring (see Figure 1). When properly installed, the antenna ring fits snugly around the circumference of the ignition lock cylinder housing. If the ring is not mounted correctly, communication problems can arise in the form of transponder-related faults.


When a stolen vehicle is recovered, the steering column is typically damaged and must be replaced. Often times, salvage yards are used as a source for replacement steering columns and sometimes insurance companies may prefer that the part is sourced as used to reduce cost. Salvaged steering columns may be in good condition; however, they may require additional repair time for a few reasons.

First, the vehicle being repaired has a sentry key system and the used column has a SKIM installed; that module will not work. The VIN from the original vehicle is burned into the module. Only one key can be used. Therefore, a new SKIM is installed which can solve the problem.

Secondly, the used steering column might not be equipped with the sentry key system. This column cannot be used because the necessary wiring for the sentry system is not installed in the column.

If you want to optimize the repair time of a steering column, consider using Authentic Mopar® Parts and make sure your customers know they have the right to request original equipment parts for their vehicle repairs.


Once the new steering column is installed in the vehicle being repaired, the new SKIM can be installed. After disconnecting the negative battery cable, remove the steering column opening cover. This piece is on top of the column between the steering wheel and the instrument panel. While taking a firm grasp of the front edge of this cover, give a quick upward pulling motion to disengage it from the instrument panel.

Next, remove the steering column upper and lower shrouds. Remove the lower shroud-to-steering column screw. Then, remove the two shroud-to-shroud mounting screws, then pull apart the two shrouds (see Figure 2). Disengage the steering column wire harness for the SKIM, then remove the one screw from the mounting tab (see Figure 1) that secures  the module to the steering column. Rotate the module upwards and then to the side away from the steering column. Remove the old SKIM from the column.

To install the new SKIM, slip the antenna ring around the ignition switch lock cylinder housing. Rotate the

module downward then toward the steering column. Install the one screw through the mounting tab (see Figure 1) to secure the SKIM to the steering column. Connect the wire harness to the module.

Next, install the steering column upper and lower shrouds. Position the lower shroud under the steering column and install the lower shroud-to-column mounting screw. Tighten the screw to 17 in. lbs. Align the upper shroud and the lower shroud, then snap the two shrouds together at the locking tab locations on both sides of the column. Install the two shroud-to-shroud mounting screws (see Figure 2). Inspect the shroud mating surfaces for any excessive gaps. Correct as necessary. To complete the installation, install the steering column opening cover. Engage the cover with the instrument panel, then push down and forward. Connect the negative battery cable.


As mentioned, the SKIM installed in a used steering column cannot work with the original keys for the vehicle, but all is not lost when the SKIM is replaced. Each SKIM is programmed with a unique secret key code. This code is stored in memory and is sent over the PCI bus to the PCM and to each key that is programmed to work with the vehicle. The secret key code is therefore a common element found in all components of the SKIS. In the event that a SKIM replacement is required, the secret key code can be restored from the PCM by following the SKIM replacement procedure found in the DRB III®, or similar, scan tool.

Proper completion of this task will allow the original ignition keys to be reprogrammed. Therefore, new keys will NOT be needed. In the event that the original secret key code cannot be recovered, new ignition keys will be required. The scan tool will alert the technician if key replacement is necessary.

The SKIM system is wonderful technology meant to keep vehicles safe and secure. Keeping it functional could be the key to keeping your customers happy.