Mechanics

TRANSMISSION PROBLEMS

2007 Daihatsu Sirion

Transmission problem
2007 Daihatsu Sirion 4 cyl Two Wheel Drive Automatic

In a regular drive (usually after 10 min drive) on an open road or in the city, there is a sudden crunchy noise and the car kind of jumps and slows down. The gear problem lights blink on and off. I would then stop the car and push the stick back and forth while the motor is not running. I switch on the motor and the car drives regularly with no blinking lights until it happens again unpredictably after a few minutes, days or even a month. This has happened in the city and the open road. I have checked it out in a certified Daihatsu garage and there couldn't find the problem.
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Tinabster
July 8, 2010.




Hi tinabster,

If the D lght blinks, a trouble code has been detected and would be recorded int the PCM. Do you mean the authorised Daihatsu dealer could not retrieve any trouble codes or none showed up?

KHLow2008
Jul 8, 2010.
D-lights went on and off even though the button on the gear stick was not activated. The garage could not find any trouble codes when it happened the first time and therefor it wasn't fixed. He was sure I had played or activated with the button on the gear stick.
Since it happened again yesterday without me having touched the gear stick I am sure that something is wrong. Today I was driving again and all was well. No blinking lights on the D/off no crunchy noises, car sounded good and went smoothly from low to high speed and back.A mystery!

Tiny
Tinabster
Jul 8, 2010.
Intermittent faults are never easy to diagnose some codes disapears once the ignition is turned off and back on so if the problem reoccurs, trouble code should be retrieved without turning the ignition off.

It could be a loose connection somewhere. Check the transmission wireharness connector for contaminations or looseness.

When problem reoccurs, note if any component is not functioning correctly.

KHLow2008
Jul 8, 2010.
Thank you so much for your professional input.I will definitely follow your directions in the matter. As for your question about other component disfunctions: after the crunchy noise the car slows down as if pushed into a different gear and doesn't get into a faster drive mode. As if I am driving 80 km/h in manual 3rd gear. Though the engine is not whining. Does that make any sense?

Tiny
Tinabster
Jul 9, 2010.
That indicates the trans has down shifted and it could be locked in 3rd.

When the situation occurs, slow down and accelerate and note if the trans upshifts.

One thing that you can do is to add an additional ground circuit from battery to transmission. Past models do have problem with groundings and an additional ground does help.
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KHLow2008
Jul 9, 2010.
I did tyr that and it is heavy going like it doesn't want to up-shift and the car bucks. What I do actually I accellerate greadually until I feel the car shifting into 4rth gear and then the driving is better. Though the D-lights are still blink on and off.
The question is if I cac get into a lifethreatening situation when the car suddenly down-shifts maybe from the fourth into first gear? Is that a computer problem or a mechanical problem I am having?
Sorry to be such a nag. But you do give good answers.
Tina

Tiny
Tinabster
Jul 9, 2010.
Hi Tina,

Problem is likely to be electrical controls. The sluggish acceleration indicates the trans is not down shifting. It most probably is stuck in 3rd gear.

This indicates an error has occurred and the transmission control system has gone into limp mode.

Get a free scan done at Autozone to see if they can retrieve any trouble codes. Let me know the exact trouble code if any found.

If none found, meybe you can try some DIY test by retrieveing the trouble codes manually.

KHLow2008
Jul 9, 2010.
Iwill do that! Thank you so very much for your help I really really appreciate it and will recommend you to all friends who have problems with their cars! You are a great help source and know your stuff.
Tina

Tiny
Tinabster
Jul 9, 2010.
You're welcome.

Hope we can get the problem fixed.

KHLow2008
Jul 9, 2010.

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