Hard shifting

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?

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.)

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.

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.

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/LUBEGARD+Automatic+Transmission+Fluid+Protectant
Purchase Online : http://www.midwayautosupply.com/p-12150-lubegard-atf-protectant-32-oz-50902.aspx

It frees stuck valves in valve bodies.

BTW, I resell the PCS that I bought for nothing :grinyes:

Rgds.

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

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.