Theory Of Operation

WARNING: This page is about a different car, the 2015 Jeep Renegade. However, it is still accessible from the selected car via links, so may be relevant.

This diagnostic checks the rationality of the calculated driveline speed based upon wheel speeds received via CAN message. This diagnostic uses three different tests which are applied separately to the odd and even gears. The first test verifies that the calculated driveline speed is not equal to 0 RPM when a gear shift is not in progress and the actual gear is an odd/even gear. The second test verifies that the calculated driveline speed is not equal to 0 RPM when there is a gear shift in progress and the target gear is an odd/even gear. The third diagnostic compares the calculated driveline speed to two different estimated driveline speeds when the actual gear is an odd/even gear and a gear shift is not in progress. The first estimated driveline speed is based upon the odd/even clutch speed divided by the gear ratio. The second estimated driveline speed is based upon the engine speed divided by the gear ratio. When anyone or more of these tests fail, the diagnostic will be considered failing.