Possible causes of jerking when starting off with an automatic transmission:
1. Problems with the torque converter:
* Sticking or worn torque converter clutch
*Low transmission fluid level
2. Electronics faults:
* Faulty speed or throttle position sensors
* Problems with the electronic transmission control module (TCM)
3. Transmission problems:
* Worn or damaged gears, clutches or brake bands
*Low transmission fluid pressure
4. Engine malfunctions:
* Worn or faulty spark plugs, ignition coils or fuel injectors
* Incorrect operation of oxygen or air flow sensors
5. Maintenance problems:
* Overdue transmission fluid replacement
*Using unsuitable or low quality fluid
* Faulty air filter
Diagnosis and troubleshooting:
To determine the exact cause of the jerking, professional diagnosis is required. Typically this includes:
* Reading fault codes using a scanner
* Checking the level and condition of the transmission fluid
* Checking the performance of the torque converter
* Checking sensors and transmission electronics
Repair:
Once the cause has been determined, appropriate repairs must be made:
* Replacing the torque converter
* Repair or replace faulty sensors or electronic components
* Transmission overhaul or replacement
* Troubleshooting engine problems
*Transmission service including fluid and filter changes
It is important to promptly address the problem of jerking when starting off, as this can lead to further damage to the transmission or engine.