Locationof the Torque Converter Clutch Solenoid

Possible causes
- Faulty Torque Converter Clutch Pulse Width Modulation (TCC PWM) Solenoid
- Torque Converter Clutch Pulse Width Modulation (TCC PWM) Solenoid harness is open or shorted
- Torque Converter Clutch Pulse Width Modulation (TCC PWM) Solenoid circuit poor electrical connection

In the tranny pan. Attached to valvebody.

This won't be a fun job. Notice this guy stated he took him about 5 hours and I think he is pretty knowledgeable. So if you are a novice auto mechanic you might want to hire this done for you.

P0743 - Torque Converter Clutch Circuit Electrical
Symptoms - Engine Light ON (or Service Engine Soon Warning Light) Possible causes - Faulty torque converter clutch solenoid valve
- Torque converter clutch solenoid valve harness or connectors
- Torque converter clutch solenoid valve circuit is open or shorted
- Low transmission fluid level
- Dirty transmission fluid
Tech notes This is an electrical problem code. Could be a problem to the harness to the TCC solenoid, the TCC solenoid connector or the TCC solenoid it self.

P0740 JEEP - Torque Converter Clutch Circuit
Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
- Transmission shift shock
- Vehicle may not shift into the highest gear

Possible causes
- Low transmission fluid level
- Dirty transmission fluid
- Faulty torque converter clutch solenoid valve
- Torque converter clutch solenoid valve harness or connectors
- Torque converter clutch solenoid valve circuit is open or shorted

When is the code detected?
Torque Converter Clutch (TCC) unlocked for 10 sec., ECM commands converter lock-up and did not record engine speed drop.

P0740 JEEP Description
The torque converter clutch solenoid valve is activated, with the gear in D4, by the Transmission Control Module (TCM) in response to signals sent from the vehicle speed and the Engine Control Module (ECM). Lock-up piston operation will then be controlled. When the torque converter clutch solenoid valve is activated, the torque converter lockup clutch will engage creating a 1 to 1 RPM ratio between the transmission input shaft and the rotational speed of the torque converter.

Lock-up operation, however, is prohibited when A/T fluid temperature is too low.

When the accelerator pedal is depressed (less than 2/8) in lock-up condition, the engine speed should not change abruptly. If there is a big jump in engine speed, there is no lock-up.

I’m happy to help further over the phone at https://www.6ya.com/expert/jeremy_69f3cc28d95bf514

you have a failure in the transmission Torque Converter clutch control circuit, (known as the TCC) this can be the control solenoid or the wiring or the actual trans torque converter.

Hi,
there are a lot of them available on ebay. I always purchase the service manual for my vehicles. Especially my jeep. 165k miles and still going without any problems. One repair with a service manual pays for itself.
http://cgi.ebay.com/ebaymotors/2000-Jeep-Wrangler-Service-Shop-Repair-Manual-OEM-00_W0QQitemZ400070848661QQcmdZViewItemQQptZMotors_Manuals_Literature?hash=item5d2614b095&_trksid=p4506.c0.m245
Thank you,
Lee

That is the torque converter clutch circuit. Have the torque converter switch and/or relay switch checked, or torque converter lock up switch.

U have a problem in the transmission torque converter clutch control circuit, most likely the solenoid switch that applies the lock up clutch of the torque converter is defective or a the torque converter itself is defective, the trans pan will need to be removed to check the problem further.

First check fluid. Make sure it's full and clean and does not smell burned (compare to another good car)
Converter failure is usually most obvious when trans shifts to OD. if shift is late or makes bang noise going in, you likely have a problem. to check lockup, after od engages, lightly touch brake, trans should momentarily shift out of od. Whining is usually due to low fluid. Also check transfer case and both differentials for proper level and leaks.