Torque Converter Clutch, No RPM Drop at Lockup

Name of Code:
Torn Conv 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 signal
d. TPS signal
e. TPS voltage low
f. TPS voltage high

Set Condition:
Torque converter malfunctions that are detected are the torque converter not locking up property when desired, and the torque converter nut 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 he 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 intermittently.

Theory of Operation:
The torque converter lockup 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 lockup 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 20.78" (T115/70-D14, Neon spare wheel size)
- Low transmission oil level or pressure
- Debris in transmission oil
- Incorrect speedo gear for the front wheels
- PTU 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
- Connector terminals/wires