Hard shifting

[sverker]

A friend came by with his Trans Sport (european name for the Venture) 2000 which when getting warm starts to shift hard. I connected my ODB-II adapter and we went off for a drive. After a while, maybe 20 minutes, the hard shifting started. I could not hear any difference in sound, i.e. no whining nor was there any trouble code set by the PCM.

I am suspecting it's the common problem with PCM solenoid, as described by TSB 00-07-30-002B, but shouldn't it set a code when that happens?

I had not yet discovered that I could add "GM specific pids" to my application (torque on android phone) but that shouldn't affect the ability to collect trouble codes being set by PCM, or?

[lesterl]

Also Pontiac version of the Venture.....

I have never had great luck capturing Trans codes, suspect it is because mine is a 97? I would suspect the PCS (the modulation valve that is common to give fits.)

[sverker]

Yes, I also suspect the PCS. He had talked to some workshops earlier that told him they had to do a rebuild for about $5k... He's going to call the dealer workshop with reference to the TSB mentioned above to see if it's something they are familiar of.

[kornjulio]

My van exhibited very similar symptoms. Had a local shop change all the solenoids in the valve body; including the PCS solenoid. Shifts much better now. Cost was around $600.

[Christophe Salvain]

Originally Posted by kornjulio

My van exhibited very similar symptoms. Had a local shop change all the solenoids in the valve body; including the PCS solenoid. Shifts much better now. Cost was around $600.

Maybe a stucked or seized PCS.
Presssure doenst go down when transmission shift.
There's 4 Pressure Control Solenoid : 1-2, 2-3, 3-4 and a master one on 4t65 – e, enhanced transmission, auto 4 spd, hmd (3,4 litres).

I fixed twice the problem on two '00 and '03 Venture and a '91 TransSport by following instruction :
- drain the trans,
- change oil, filter and gasket,
- add Lubegard Automatic Transmission Fluid (ATF) Protectant http://www.lubegard.com/C-112/LUBEGA...uid+Protectant
Purchase Online : http://www.midwayautosupply.com/p-12...-oz-50902.aspx

It frees stuck valves in valve bodies.

BTW, I resell the PCS that I bought for nothing

Rgds.

[sverker]

Interesting. Did you do a full flush of the system or just dropping the pan and changing the oil you got out there?

[Christophe Salvain]

Originally Posted by sverker

Interesting. Did you do a full flush of the system or just dropping the pan and changing the oil you got out there?

#2
My mechanic just dropped the pan and changed the oil in it only.