Putting Cherokee owners back in control of the 1-2 shift.

By Bruce W. Smith & Kevin Williams

Photos by Bruce W. Smith

Cherokee owners have undoubtedly felt the frustration as their vehicles begin to gain a little too much speed when going downhill. They reach down and drop the transmission lever into the 1-2 position, and then it happens: At about 12 mph, the transmission drops into First, sending the shot-gun passenger into the windshield face-first and the rear passengers plowing into the front
headrests. If the road happens to be wet, the rear tires can also attempt an abrupt about face. 

Unfortunately, Jeep didn't engineer an easy way to lock the Cherokee's transmission into Second to prevent the sudden down-shift into First. A company named Aftermarket Innovations (Dept. OR, 4326 Glencoe St. NE, Salem, OR 97301, 800/528-6900) has a new product called the CompuShift Plus that successfully does this. CompuShift Plus is the brain child of Cherokee owner Jim Nasset, who experienced the sudden-shifting syndrome during a hunting trip and decided to invent this device.

 The unit allows the driver to control the transmission computer by interfacing a separate control device that uses a Comfort/Power switch to manually control shifting into First and Second.  The CompuShift Plus is activated when the transmission is moved into the 1-2 position. With the transmission mode switch set the Comfort position, the transmission will down-shift to Second and stay there until the Jeep is stopped.  


It will also take off from a dead stop in Second (which is great on icy roads) but will downshift into First when the gas pedal is depress more than one-third down. In the Power mode, the CompuShift Plus stays out of the loop, letting the transmission, respond as the factory had intended downshifting into First at the factory's pre-programmed rpm. CompuShift Plus installs in about five minutes by splicing into the factory transmission control unit (TCI) under the dash on the right-hand side with 6 quick-splices. 

We installed a test unit in an '89 Cherokee, which took about fifteen minutes to hook up, self-test, and photograph. Test driving entailed taking the Jeep to about 40 mph and then shifting into the 1-2 position with the CompuShift Plus in the Power position. The Cherokee down-shifted into Second with no problem and then on to First at approximately 28 mph. We repeated the test with the mode switch in the Comfort position and down-shifted again into 1-2.

 The Cherokee responded with a smooth transition to Second and stayed there until the vehicle was stopped. This time the accelerator was depressed lightly and the Jeep pulled from a stop in Second. With a little more gas pedal, the transmission quickly responded with a energetic down shift to First and accelerated like normal. The CompuShift Plus retails for $169.95.




Manufacturers Note:  The Power/Comfort switch was discontinued by Jeep in the 1992 year model vehicle.  The CompuShift Plus kit includes a pre-wired switch for installation on the the 1992 and newer vehicles.

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