Hello !

 

In order to have a proper image of the situation of the car, I will tell the full story.

In April 2022 I bought a skoda octavia 2 1.4 tsi fl (2009). The engine is in good condition, low mileage, imported from Germany with all the maintenance done at the dealership, good equipment. On the way back home, the gearbox failed (manual 6+1), first and second gear pop out and make a grinding noise. Ok, no problem, i changed the gearbox, second hand no issues. After the gearbox change i saw that the cruise control is not working anymore (with the original / first gearbox, cruise control worked perfectly). I went back to the shop and they told me that there could be multiple problems, but not with the gearbox. I went home, put the tester on the car, and i see Clutch switch- implausible signal. I did not have the time or money to fix it so about a month passed and about 500 km. All of a sudden, after a cold night, i want to start the car, the car starts and my dash is like a Christmas tree. Abs light, brake light, ESP. The abs module died, changed with a second hand one that supports all the cars equipment (hill assist), i did the coding myself, got the money to change the clutch switch. Same error, cruise control still doesn't work. First switch was bought second hand and i thought it was bad as well. I said no more cheap stuff. Bought the whole thing (clutch pump and switch), i installed them and.. still nothing, same error, clutch switch implausible signal.

 

The cruise control behaves like this:

From what i know, the cruise control should work from the first gear

First gear - nothing

Second gear - nothing

Third gear - Between 2000 and 2200 rpm, the cruise control will engage but after a few seconds the car will jerk and the cruise control will disengage and it will remain that way for a few days.

4th, 5th,6th gear - nothing

On the tester, the clutch is permanently engaged, i have to press 3 4 times to show 0 but instantly goes back to 1.

 

Also,

When i change gears and I am at a high rpm, when I press the clutch, the car will rev itself up (I'm not pressing the throttle).

 

I really don't know what to do at this point, it is worth mentioning that the car had an electric problem regarding the locking button inside the car, near the armrest.

 

The clutch switch is located on the clutch pump, not inside the car on the clutch pedal.

 

In addition to all of the above, 2 days ago i got 1 more fault code, Manifold / Barometric pressure sensor (g71) / (f96). I changed the sensor but the fault code remains. I cleared all DTC and nothing. In everything i did to the car i used vcds.

 

Thank you! 

Consider a wire/connector has been damaged when replacing the gearbox, especially any strained going into the fuse box in the engine compartment.

 

First I'd try disconnecting the battery and ensuring no residual charge remains in the car's electronics before reconnecting to eliminate any computer gremlins.

5 hours ago, MicMac said:

Consider a wire/connector has been damaged when replacing the gearbox, especially any strained going into the fuse box in the engine compartment.

 

First I'd try disconnecting the battery and ensuring no residual charge remains in the car's electronics before reconnecting to eliminate any computer gremlins.

I already removed the battery and waited for half an hour, i put it back, checked the fuse box and everything is ok. By the way, i forgot to mention how i got the Manifold pressure sensor fault code. I had to remove the battery for a quick charge and went i put it back in, i wanted to remove the errors. Then i saw the manifold sensor fault. 

 

Is there a connector on the gearbox on a manual transmission? I'm asking because i was thinking the same thing (electric problem) and i asked around. The answer was that only automatic transmission has a connector on it, therefore on a manual it's not possible.

When you disconnect the battery, turn the ignition on and switch things on e.g. headlights/horn/hazard lights, this will deplete any stored power in control units etc.

 

The only electrical connection to the gearbox is for the reverse gear switch.