Pulsing acceleration intermittently. Is this a bad TCC??

**jeepers** · 09-23-2021

I've read a number of discussions and articles that suggest that the problem I'm having is caused by a bad TCC solenoid. The symptoms most often include pulsing under light load. I get this under light load and just after a shift up or down.
It doesn't happen every time. Actually, it used to be extremely rare but the frequency is definitely increasing.
Otherwise, the car runs well. From a stop to cruising speeds, it's all good as long as it's a steady foot. Hard acceleration at all points on the speedo are good. Shifting seems to be fine in all gears in both directions.

Can anyone confirm the cause?
https://youtu.be/abIH4ltBfMk
https://youtu.be/P__VU38zys8
https://youtu.be/CAkQ5rBN0iM

Thanks

**FordMan77** · 09-23-2021

You're video is private, but if you get an RPM surge under a load then likely the TCC is dying. My 00 GT has been doing this for a few years now and I've been babying it along so far. I turn off my traction control which seems to help it some but I can still make it do it when I get on it hard enough. I also just drive around in 3rd and manually shift it into OD when I'm going to be above 50mph for a while, otherwise it just hunts around and I hate the excess shifting.

Granted I have a high mileage trans. but it started out just like yours and now it'll slip/bang in first if I jump on it from a stop and it will slip on a hard downshift too. It's just time for a whole rebuild at this point for me. You may be able to extend the life of yours with a Trans-Go shift kit and filter/pan drop fluid change. I've been running the kit in mine when it started acting weird and it's still going. And no, I didn't do the whole kit just the 1-2 and 2-3 accumulators. Didn't touch the rest.

**jeepers** · 09-24-2021

Sigh. Thanks FordMan77. I've fixed the videos.

My TCS and ABS are not working at the moment (likely the module). They haven't worked for a couple of years and is on my list but hasn't caused me any trouble.

I don't have any trouble shifting...at least not yet anyway. I guess that's coming.
Did you have any codes? Most of the TCC related articles indicate P074x codes. I haven't had any.
For the cost of the kit, I might just do it anyway.

Thanks

**FordMan77** · 09-24-2021

Your TCS and ABS are likely due to a bad wire or front hub. The harness that goes from the wheel hub in front and runs along each control arm goes bad and corrodes internally, thus shutting of ABS and since the TCS is tied to the ABS you get both lights. Might be worth checking out. While the modules can go bad it seems to be more prevelant on the 04+ cars which judging from your video yours is a 97-03.

Honestly I haven't checked. As long as my CEL stays out I don't look.

The kit really extended the life of my trans. Was totally worth it, plus you change do a pan drop/filter change while there and get some fresh fluid in it. And NEVER flush that transmission. Just refill what came out of the pan and move on.

To see if it is the TCC, when it starts the bouncing RPM thing keep your foot steady on the gas and lightly tap the brake pedal with your left foot (enough that it will make the brake lights come on) and see if the RPM bounce goes away. Tapping the brakes unlocks the converter and should stop the bounce for a minute until it relocks.

**jeepers** · 09-27-2021

Good morning, FordMan,

You are correct. It is a 2001. Both front hubs have been replaced so that rules that out. I've also low-tech checked the wiring by shorting the wires at the module connector then checking for resistance at the wheel. All four wheels read 0 ohms. Well, they do now. The wiring from the front right wheel was in terrible condition. I replaced the bottom 2 feet of wire to get successful continuity.
All that said, it's probably time to recheck.
I'm just getting set to throw some paint at the car this weekend. So long as I don't bugger that up too badly, I'll add the transmission kit to my short list of repairs. It does make sense from a preventative point of view.

Thanks again.

**digitalgpbandit** · 09-28-2021

Could be a bad connection at your MAF sensor. The wires get very brittle and may cause a bad connection. I would unplug your MAF and see if it runs any different. GM makes (or used to make) a pigtail connector for it. Also if you don't have a check engine light scan to see if there are any pending codes. If its intermittent it may not cause the light to come on, but may be enough to store a pending code

**jeepers** · 09-28-2021

Hey digitalgpbandit, I'll double check that. I did change the MAF recently so it's certainly worth a double-check.
@FordMan77, I did as you suggested and ever so lightly tapped the brakes while it was surging and it had the expected result...it steadied out. It also changed gears but I'm guessing that's expected as well.

As for codes, I haven't seen anything related to this yet. I check every couple of weeks since I've got a P0440 that I also need to look at but for now am just clearing. My list of crap to fix is becoming a bit unmanageable.

**wowitsfast** · 09-28-2021

Day in the life of a grand prix owner

Sent from my SM-G981V using Tapatalk

**jeepers** · 09-30-2021

Funny thing. I checked for codes two nights ago with my $40 reader and only had the usual P0442
I stumbled across a printout from Enginuity scanner from last year and, lo and behold, P1571.
Sometimes my stupidity amazes even me.

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