10 Most Common Transmission Problems

[pwuser159753061061]

@Xulfiqar AOA
Can u plz suggest what can possibly be the issue with my Altis 2010 not shifting in O/D. Replaced gear box recently but after that having this issue and unable to resolve or find out the case. On motorways while driving over 120 kmph heat bar gets to full even water is cold in radiator RPM goes over 4000rpm but shifting is not made. Is there any thing u can suggest me to do

[pwuser161643535944]

Asslam o alaikum
Have you got any solution brother
If yes please share it
Because i m facing the same problem

[inam45]

I am having issue with automatic transmission 2012 corolla 1.6, Works perfectly fine only have issue while gear shifting and sometimes delay while shifting from 2-3rd gear and vice versa, RPM randomly spikes also. What could be possible problems ? P.s have changed gear oil already and no smell and everything was clean inside too oil color was normal not so good not too bad.

[uzeemujeeb]

the workshop shall connect the scanner to vehicle and extract the codes. RPM spike occurs due to vaccuum leak.

[inam45]

There was only one code P1604. Startability Malfunction which was cleared after tuning plugs change, throttle cleaning and MAF sensor cleaning and now there are no codes. Is there any chance VSS Speed Sensor can cause this issue? Because its clip was broken and was replaced but i have asked multiple electricians and they all say this has nothing to do which this issue !

[uzeemujeeb]

did the electrician soldered the electrical connection to grip or used insulation tape. There is likely chance that it may be malfunctioning. @Xulfiqar @hassan1991

[inam45]

He replaced the whole grip by cutting wires and then used the insulation tape.

[uzeemujeeb]

used the insulation tape

if you have access to a soldering iron and heat shrink tubes please redo the connections and test your vehicle. It may fix the issue.

[Xulfiqar]

what kind of electrician did you visit? - the wiring plug can be replaced without cutting any wires quite easily.

[inam45]

You mean the connection on the grip! the whole grip was changed should i do it on the new grip ?

[inam45]

i guess he didn't wanted to put an effort and simply cut the wires of the grip and got new grip with wires and then connected those wires to the wires of car, i got the grip checked again from two different electricians and they both check it with that desi light tester none had the digital meter and they say grip and wires are working fine and it can't be this sensor its something inside transmission and i am being bounced around mechanic says its eletric and eletric says it mechanic.

Should i replace the whole VSS speed sensor !

Update: RPM Spike and random acceleration happens more on the uphill and only when i push the car upon hard reving from 0 i feel gatka around 30km/h and then feel gear changes and car is normal, when i drive with very light foot everything is smooth nothing but the random RPM spike would happen for no reason for split second and then get back to normal.

[Xulfiqar]

That is really bad, a wiring plug can be repinned with a new plastic housing quite easily.

Its done around the world everyday., even in small workshops.

[inam45]

So Xulfiqar bhai what should i do now ?

[Xulfiqar]

You can test the speed sensor with an oscilloscope, infact you can test those parameters on a scan tool like techstream or a good scanner too.

If you are seeing input and output speed properly then its not the sensors at fault.

You may also have a selector mode switch problem or even a solenoid connector problem. Its troubleshooting involves probing a few circuits and seeing when they malfunction. This can be done even with oldschool logic analysers to record data.

Stop visiting hit and trial mechanics. Find out good shops and talk to them first how they repair.

[Moderator]

[inam45]

Here in Abbottabad we mostly have these hit and trial mechanics and electricians. I can't even find an electrician with proper meter to test they all test with that desi light tester if any one know please let me know i'll really appreciate it for past few weeks i have been to many and some suggest me to get fuel pump replaced and some tells me to get catalyst converter clean and mostly said to change transmission oil and plugs, which i already did i finally got myself obd scanner and checked the speed, engine acceleration and rpm they all sync together on it no sudden drops or spikes noticed anywhere so now i am sure its not VSS speed sensor however i'll check again from 0-100 as i only check it in streets anyways i think it has something to do with transmission because i have noticed it only happens in between 40-80 speed window and on constant foot to be exact it happened mostly at 60km/h speed car jerk and in between 40-80 i feel random RPM spike feels like car gets Netural and then shifts and then it smooth in 80 and above. Upon googling it could be one of the transmission solenoid but then again you are the expert please suggest me what could it be ?

If anyone know any good transmission mechanic in Rawalpindi or Islamabad i would really appreciate it.

[inam45]

@def3nder can you please suggest any good transmission mechanic here in Abbottabad ! i have already been to Asad he now mostly have new boys and he would let them experiment on cars and multiple people recommended me Mughal gear wala who is behind chinar motors he only deals with manual cars and suggested me to goto pindi as i won't find any good one here and what are your thought about go mechanic on Murree road which has newly opened !

[Xulfiqar]

Its not as simple as “ye kardo to set hojaiga” with an automatic transmission. The data needs to be read and correctly interpreted and understood before repairing.

[def3nder]

which electrician did you visit?

[def3nder]

Xulfiqar bhai, you dont have any idea whats going around, even in 3s dealerships. Even, no proper expert mechanic of efi mehran. If have any carburetor engine in the car, then life is easy for you.