INSTALLING THE FACTORY TPMS ON OTHER WJ MODELS

The upgrade can be accomplished in 3 easy steps:

1. Replace EVIC module (module only, you do not have to swap-out the entire console)
2. Replace existing valve stems with the TPMS stems/sensors (4 tires plus spare)
3. "Train" system (for recognition of each tire location on vehicle)

This option can be added to all model years of WJ vehicles, although it can be rather expensive if the parts are purchased new from a dealer. The EVIC module inside the console must be replaced with the advanced version than includes the TPMS circuitry. There is no extra wiring, the existing module is simply removed and replaced with the new one. Most EVIC modules are interchangeable. If you have the standard EVIC, for example, you can upgrade and install either of the two step-up models. One adds HomeLink, and the other adds HomeLink plus the TPMS. The old module can be sold if desired to slightly offset some of the upgrade costs.

There are 3 different style modules produced for the WJ, as shown in the chart below:

To remove the EVIC module you need to detach the overhead console. The console is held in place with one phillips head screw and two spring clips. The screw is located near the windshield side, and should be removed with a non-magnetic screwdriver as to avoid interference with the compass. Next, grab the console from the sides, wedging your fingers underneath it, and carefully and firmly pull it straight down.

The EVIC module, shown from the back and the front in the photos above, is attached to the console with 4 phillips screws. There is one small wire harness to unplug, located near the back of the module. After the new module is installed, the compass zone info may have to be re-entered into the EVIC. Note that the new EVIC module does not come with the front lens, you'll need to pull that off of your old unit and install it in the new one, a very easy process.

Tire pressure sensor module.

Inside view of installed sensor.

The 5 sensors are then installed into the tires of the new vehicle. The Factory Service Manual details exact instructions and cautions for mounting the sensors. The system must then be retrained with the special magnet so that the EVIC learns the specific location of each transmitter. Training directions are shown below.

RETRAINING THE TIRE SENSORS:

The sensor transmitters can easily be retrained by anyone and takes just a couple of minutes.

1. On the overhead console, use the "Menu" button to advance to the "Retrain" option in the EVIC menu.

2. When "Yes" is selected, training will begin, starting with the left front tire.

3. Place the special magnet (Miller tool # 8821) momentarily on each valve stem, one at a time, in clockwise order (LF,RF,LR,RR,SP). You'll have 60 seconds to place the magnet on the first tire stem and 30 seconds for each of the other four, the spare being last. As each tire location is "learned", there is a confirming horn chirp. That's it, the correct tire pressure will now be displayed for the corresponding tires.

The special magnet tool used for retraining is included with those vehicles in which the factory has installed the TPMS option. The magnet can also be purchased for around $25, otherwise a pair of 6" or so speakers with good size magnets will do the trick.

Tire pressure sensor re-learn magnet

Placement location for retraining

TIRE PRESSURE SYSTEM TEST

The following test can be used to verify two functions. One, that the tire pressure sensors are transmitting properly and two, the EVIC module is receiving these transmissions accordingly. Using the STEP button on the overhead console, scroll to the blank display, then press the RESET button for five seconds, a beep will sound indicating the start of this test. The vehicle icon and transmission counters will now be displayed, (same display as individual tire pressure except counters replace tire pressure values).

Upon entering the test mode, the EVIC will clear the sensor counter and each time a sensor signal for a road tire is received, the EVIC will update the counter value (according to the service manual, the vehicle must be driven at 25+ mph to transmit, however, the vehicle I tested counted with the vehicle parked and ignition on). The counter values should all read the same value. If any of the road tires indicate a different value than another tire sensor, this is a sign of a problem. Replace the appropriate tire sensor and retest the system. This test will continue until any of the overhead console buttons are pressed or the ignition is turned off.

Further technical, diagnostic and safety information can be found in both the Factory Service and Body Diagnostics Manuals.