Set Condition
WARNING: This page is about a different car, the 2017 Jeep Cherokee. However, it is still accessible from the selected car via links, so may be relevant.
- During Gear Shifts:
- A symptom is detected if the measured gear ratio exceeds the gear ratio range.
- If a symptom is detected during downshifts requiring the engagement of a dog clutch or during upshifts, the diagnostic system aborts the gear shifting and the gear from which the shifting has been started is engaged. After a calibrated number of symptoms have been detected a failure is stored and the diagnostic system engages a calibrated gear.
- If a symptom is detected during a downshift requiring the engagement of a dog clutch, a fault code is stored indicating the associated dog clutch.
- In Fixed Gears:
- If the output speed is greater than a threshold then a symptom is detected if the measured gear ratio exceeds the gear ratio range for calibrated amount of time.
- If the output speed is lower than this threshold, then a symptom is detected if the absolute difference between output speed multiplied by the fix gear ratio of the actual gear and input speed exceeds a threshold for a calibrated amount of time.
- If a symptom is detected while driving in a fixed gear, the diagnostic system commands an up shift to the next gear. After a calibrated number of symptoms have been detected, a failure is stored and the diagnostic system engages a calibrated gear. This gear is monitored as well and if a failure is detected for this gear, an alternative gear is engaged and so on. The selection of alternative gears follows a calibrated logic. The aim of this logic is to detect a damaged clutch and to finally select an alternative gear that consists of a combination of clutches in which the damaged clutch is not involved. If a further failure symptom occurs in this final alternative gear, a failure for general transmission ratio malfunction is stored.