Possible causes of impact when turning on the automatic transmission in an Opel Insignia:
1. Insufficient or contaminated transmission fluid (ATF):
* Check ATF level and add or replace if necessary.
* Dirty ATF can cause slippage or excessive friction when shifting gears.
2. Faulty torque converter:
* The torque converter transfers power from the engine to the transmission.
* If it is defective, shock may occur when shifting gears.
3. Worn or damaged friction packs:
* Friction packs are used to engage gears.
* If they are worn or damaged, it may cause slippage or shock when shifting.
4. Faulty solenoids:
* Solenoids control the flow of ATF in the transmission.
* If they are faulty, it may cause improper shifting and shock.
5. Electrical problems:
* Electrical problems, such as faulty sensors or wiring problems, can prevent the automatic transmission from operating properly.
* This may cause shock when shifting.
6. Faulty Transmission Control Unit (TCU):
* The TCU is the computer that controls the automatic transmission.
* If it is defective, it may cause improper shifting and bumps.
Recommended actions:
* Check ATF level and condition.
* Identify trouble codes using OBD2 scanner.
*Consult a qualified mechanic for further diagnosis and repair.
* Avoid aggressive driving and sudden gear changes until the problem is resolved.