So I got my car back from the trans. shop today and I still have the original surging problem. So either the tranny wasn't bad and it'* an engine problem or the trans. shop didn't properly rebuild it.

It'* under warranty and I'm taking the car back on monday

I replaced the TPS before it went into the trans. shop.

Any Ideas??dh2

What speed is it surging? About 45?

Before going to trans. shop 45-55 mph. I seem to remember the problem occuring at 55-60 mph today. I'm going to check the TCC switch again on the way home from work tonight. Is it possible that the pcm needs to be reset after trans. rebuild? If so maybe they forgot to do that. I dunno, just grasping at straws and angry, frustrated, disappointed. I just spent a BIG chunk of money for the rebuild.


The surging doesn't seem to be as bad as before but it'* definitely still there...

The PCM will have reset during the rebuild because the battery would have been disconnected. Check the TCC switch. I still think that'* the problem.

I'll pull the switch to test after I get home from work tonight. What I don't understand is since the TCC switch is linked to the brake pedal how does that affect TC lockup under load? (The problem doesn't occur when I push the brake pedal).

If the switch is not engaging all the way, the TC will go in and out of lock up.

Ok, so when the switch plunger is out (brake pedal released) is the circuit open or closed? I'm wondering if an open or closed circuit is used to signal the TC to go and out of lockup. Sorry if I'm being redundant, it helps for me to understand the circuit.

I have the same Surging problem in a 2000 SSEI. Been chasing this for a while!
I still drive it 100 miles a day but would like to find the root problem. I think a lot of the SSEIs have this problem! I have also done most of the same trouble shouting as you!

** I think my next plan is to change the EPC and the valve body in the trans! **
** While in there it is a good idea to also change the TCC! **

But this looks like a full day of labor?

There is a GM TSB # 020730048 for a PCS replacement

On the drive home last night I did the TCC solenoid road test and it tested good. I pulled the TCC switch under the dash and tested it this morning and it tested ok as well. The only thing is the resistance values were a little high with a closed switch, .5-.7 ohms. Is that a problem? Does the tcc switch have to function in sync with the stop lamp switch mounted above? (Can a defective Stoplamp) SW induce a problem into the TCC circuit?) The car still surges BTW.

Yep I just had my tranny rebuilt and the problem remains... They put in a new torque converter, clutches, bands, 1 drum, replaced the splined (output shaft?), new solenoids, shift kit, amongst other things. So if I can find any other problems this weekend I'll go back to the transmission shop that did the work and talk to them. At 73k miles I suppose a rebuild is a good idea but it didn't solve the surging problem as the tranny shop would have me believe.