Torque Converter Clutch, No RPM Drop at Lockup
NAME OF CODETorque Converter Clutch No RPM Drop at Lockup
WHEN MONITORED
When all of the following steps are taken.
1. Run vehicle in the third gear with torque converter unlocked for about 10 seconds.
2. Apply heavy throttle until torque converter locks and then keep the torque converter locked for about 5 seconds.
3. Vehicle speed < 70 MPH during steps 1 and 2.
4. None of the following matured or maturing trouble code conditions:
a. TCC solenoid circuit
b. Any cam/crank related code
c. Vehicle speed signals
d. TPS signal
e. TPS voltage low
f. TPS voltage high
SET CONDITION
Torque convener malfunctions that are detected are the torque converter not locking up properly when desired, and the torque converter not unlocking property when desired. A minimum amount of improvement in torque converter efficiency is expected after the torque converter is locked. This expected minimum improvement will not be seen when the torque converter is malfunctioning. Two consecutive test failures over two trips will store the trouble code. Driving on mountainous terrain can cause this code to occur intermitently.
THEORY OF OPERATION
The torque converter lock-up system locks the crankshaft to the output shaft of the transmission when vehicle road load is stable and transmission is in third gear. This action reduces transmission oil heating, and improves fuel economy and thus emissions. The lock-up system is controlled by the powertrain control module.
POSSIBLE CAUSES
- Front wheel(s) size(s) is (are) bigger than 23.51" (185/65-R14, standard Neon wheel size) or smaller than 20.75" (T115/70-D14, Neon spare wheel size)
- Low transmission oil level or pressure
- Debris in transmission oil
- Incorrect speedo gear for the front wheels
- PTL solenoid not securely connected or stuck
- Malfunctioning lock-up valve in transmission
- Worn out friction material on friction disc in torque converter
- Failed gear box, differential, or drive shaft contacts
- Powertrain control module failure
- Connector terminals/wires