TCC Plug on GTGP2000

[monkeylizard]

I've begun experiencing the hesitation described in other posts that occurs just after an upshift and particularly when there is a load on the engine (like uphill) and the RPMs are around 2000. I've changed plugs with no effect. From the other posts I'm thinking the Torque Converter is doing that lock/unlock trick.

The TCC Plug is mentioned in some posts for older models, but I don't know where that is in the 2000. Is it still accessible? I'd like to try that and see if that fixes the problem. That would confirm or eliminate the TCC Solenoid, right?

If it doesn't work, it could still be the TC, but maybe caused by a leaky manifold intake gasket, right?

88,000 miles
2000 GT
---------

[BNaylor]

Originally Posted by monkeylizard

I've begun experiencing the hesitation described in other posts that occurs just after an upshift and particularly when there is a load on the engine (like uphill) and the RPMs are around 2000. I've changed plugs with no effect. From the other posts I'm thinking the Torque Converter is doing that lock/unlock trick.

The TCC Plug is mentioned in some posts for older models, but I don't know where that is in the 2000. Is it still accessible? I'd like to try that and see if that fixes the problem. That would confirm or eliminate the TCC Solenoid, right?

If it doesn't work, it could still be the TC, but maybe caused by a leaky manifold intake gasket, right?

88,000 miles
2000 GT
---------

A separate TCC plug does not exist. All TCC commands along with all other signals from the PCM, etc. go through one 20 way connector located on the top of the driver's side of the transaxle. It cannot be disconnected as in the past, however, it can be properly troubleshot if you have a GM or 4T65E service manual.

Engine problems could make the tranny look bad so thats a possibility.








Thrasher CAI, DHP v1.0 PCM, SLP Headers,
3.25 SC pulley, CAIT GMAF, 2.5 DP/Hi-Flow CAT,
u-bend delete, 160 TS, ZZP Stage 1 72mm TB,
TB spacer, MSD 8.5mm wires, Autolite 103,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials
1/4 ET: 13.210 sec. @ 104.490 mph
0 - 60 ft: 1.945 sec.

[monkeylizard]

I also saw a post suggesting that I apply the brake when the problem occurs (I assume left foot the brake and continue to accelerate with the right) and that this will make the TCC disengage. If that works, then it probably is the TC, right?

[BNaylor]

Originally Posted by monkeylizard

I also saw a post suggesting that I apply the brake when the problem occurs (I assume left foot the brake and continue to accelerate with the right) and that this will make the TCC disengage. If that works, then it probably is the TC, right?

The best way to test the torque convertor lock/unlock function is to do level cruising. In OD (4th gear), accelerate to over 40 mph. Then gradually increase to over 45 mph and up. Watch the tach, it should eventually dip 400 - 500 rpm indicating its locked. Whenever you apply the brake it should unlock. Normally with speeds below 45 mph the torque convertor is inhibited from locking up anyways.









Thrasher CAI, DHP v1.0 PCM, SLP Headers,
3.25 SC pulley, CAIT GMAF, 2.5 DP/Hi-Flow CAT,
u-bend delete, 160 TS, ZZP Stage 1 72mm TB,
TB spacer, MSD 8.5mm wires, Autolite 103,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials
1/4 ET: 13.210 sec. @ 104.490 mph
0 - 60 ft: 1.945 sec.

[monkeylizard]

Dealer mechanic took it for a quick drive. Suggested that I try changing the Throttle Position Sensor (TPS) first. He said he found a GM bulletin suggesting this first, since it's an $80 part instead of a $1200 tranny job. Tried it, but no change. I'm going to check the fuel pressure this weekend (per other similar posts). I'll post back with results.

So far I've changed all 6 plugs, the TPS, and the fuel filter. No change, but except for the TPS, the others needed to be done anyway (90K miles).

[BNaylor]

Originally Posted by monkeylizard

Dealer mechanic took it for a quick drive. Suggested that I try changing the Throttle Position Sensor (TPS) first. He said he found a GM bulletin suggesting this first, since it's an $80 part instead of a $1200 tranny job. Tried it, but no change. I'm going to check the fuel pressure this weekend (per other similar posts). I'll post back with results.

So far I've changed all 6 plugs, the TPS, and the fuel filter. No change, but except for the TPS, the others needed to be done anyway (90K miles).

If the fuel pressure checks out OK and if you haven't done it already check out your MAF sensor. Try cleaning it with electrical contact cleaner first. If that doesn't work it may need replacing.

The only other thing that comes to mind would be the CAT convertor. I had a bad CAT once and it made the tranny do weird things.










Thrasher CAI, DHP v1.0 PCM, SLP Headers,
3.25 SC pulley, CAIT GMAF, 2.5 DP/Hi-Flow CAT,
u-bend delete, 160 TS, ZZP Stage 1 72mm TB,
TB spacer, MSD 8.5mm wires, Autolite 103,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials
1/4 ET: 13.210 sec. @ 104.490 mph
0 - 60 ft: 1.945 sec.

[monkeylizard]

OK,
The problem is worse. Now it happens all the time. Additionally, it has started shifting real hard after driving for about 20-30 minutes.
Took it to a different dealer this morning and they drove it around with the diag hooked up. Told me it's a pressure control valve. the tranny does not have to come all the way out because they can get to it from some access panels after taking some other parts out. $650 this time instead of $1200 quoted for the tcc solenoid replacement.

Gonna give it a go and I'll post back the results.

BTW, I never did get around to testing the fuel pressure.

[BNaylor]

Originally Posted by monkeylizard

OK,
The problem is worse. Now it happens all the time. Additionally, it has started shifting real hard after driving for about 20-30 minutes.
Took it to a different dealer this morning and they drove it around with the diag hooked up. Told me it's a pressure control valve. the tranny does not have to come all the way out because they can get to it from some access panels after taking some other parts out. $650 this time instead of $1200 quoted for the tcc solenoid replacement.

Gonna give it a go and I'll post back the results.

BTW, I never did get around to testing the fuel pressure.

The pressure control solenoid (PCS) is a possibility. $650.00 is better than the $1200 quoted which is a rip off for this type of work. Labor costs for either solenoid should be the same. Same amount of work involved and same removal procedure. Both the TCC-PWM solenoids and PCS are located on the left hand side of the valve body under the tranny side cover. They are located about 2 inches away from each other. You might consider getting both solenoids replaced while they have it apart just to be safe.

[monkeylizard]

OK, as promised here are the results. Dealership replaced both TCC and PCS. Reading between the lines on the notes on my paperwork, this fixed the hard shifting, but not the hesitation or "chuggle" as they called it. They disconnected the battery cables and let it sit overnight. apparently they found this trick in a GM bulletin. It will cause the TCC to reset and start functioning properly.

Everything is great now. If the hard shifting hadn't started, I probably would not have needed any parts at all, just an overnight with no battery. Anyone else with the hesitation problem might want to give this a try before paying $$ for tranny work.

[richtazz]

Thanks for the tip on the battery trick in case I ever need it. I don't remember seeing a TSB about it, but hey, if it works and is free.......

[BNaylor]

Originally Posted by richtazz

Thanks for the tip on the battery trick in case I ever need it. I don't remember seeing a TSB about it, but hey, if it works and is free.......

It would be nice to get the GM TSB number on that Rich. I haven't seen it either. I'll check with Troy1 maybe he has it.

I know Tapps (adaptive shift) info should be cleared out of the PCM after a PCS job which will cause a reset.