Range Rover Sport - Check Engine light on - Vibration
A 2008 Range Rover Sport came in the shop with a complain of check engine light on and an intermittent vibration at cruising speeds.
To diagnose this problem first we checked for faults in the transmission control module and found a code P0741 for torque converter clutch circuit performance. To verify that it was the torque converter clutch solenoid and not a problem somewhere else in the circuit the multi connector at the transmission was disconnected and the resistance of all solenoids tested. Found excessive resistance on the torque converter solenoid as well as on shift solenoid #2, but no fault was set for the other solenoid. A look at the transmission fluid also showed the fluid very dark and smelled burnt.
Since removal of the solenoids require to take the transmission valve body out, we suggested to replace all the solenoids as well as the transmission filter and fluid. After the repair the transmission adaptation values at the transmission control module were reset and the vehicle road tested to verify that the transmission worked smoothly and fault codes came back.