: TCC Stuck Off



jcresciSTS
07-30-09, 03:03 PM
I posted in the big TCC thread but no one has replied back...

Basically, the TCC has been on at least since July 08, according to the previous owners records. I got the car in May 09. Service Engine light came on a week after buying it and it showed this code. I reset the light on Tuesday morning and it came back on this morning.

Yesterday, when the light was off, I did the test. I drove at 60mph and tapped the brake and the rpms didn't move. I will try the test again today with the light on this time. My mechanic said to leave the light on so he can check the codes with me, I will probably go see him tomorrow.

Also, the light was off, when I bought the car I had to have it smogged and passed easily. Gas doesn't seem to suffer, 24/25 (65mph cruise on), I started getting 26/27mpg but I'm not sure if that was because I turned the light off or because I changed the spark plugs (same day), I will check today on my way to work.

I appreciate all the help you guys have given me...

Submariner409
07-30-09, 04:51 PM
Both our cars have the same final drive and gear ratios, so........

Your engine rpm at 60 should be 2000, maybe 2100, highway steady cruise. Maintaining your foot on the gas pedal, a slight press of the brake pedal should allow rpm to increase by 300 +/-.

I'm headed up U.S. 301 in an hour for a 50 mile run to a restaurant - I'll have Karen write down the moderate acceleration shift rpm's and steady state conditions and post them at 10 or 11 tonight. (Plus the rpm change at TCC engagement......)

jcresciSTS
07-30-09, 06:19 PM
Ok, so the RPM is SUPPOSED to increase, I thought it wasn't :(

I believe when doing 65 with Cruise my rpm's are at about 2100

Good news is I got my Coolant Exchange done and AFT Exchange at the local GM dealer, $309 total and the amazingly I benefited from these things:

Tranny feels a bit smoother when shifting and changing gear...car does go up a bit but not as jerky.

Engine is really quiet now, my lifter tick went away and so did the belt hiss.

Doesn't rough idle as bad, its a lot calmer, I'm hoping the wires will solve it completely

Submariner409
07-30-09, 09:05 PM
OK, Here we go. Average of 3 moderate-throttle standing starts to TCC engagement, trying to hold the same throttle opening (~30 %) for each run.

1 - 2 shift @ 16 mph 2200 rpm
2 - 3 shift @ 38 mph 3000 rpm
3 - 4 shift @ 56 mph 2800 rpm
TCC engagement @ 62 mph, 300 rpm drop.

60 mph = 2000 rpm (Tap the brake and it goes to 2300)
75 mph = 2450 rpm.

Light throttle slow acceleration TCC engages at about 42 mph, 300 rpm drop.

(Glass of house Merlot, 8 oz. filet (rare) and a broiled crab cake with baby asparagus and red potatoes on the side. Seniors night at the Kitty Knight House, 50% off = $16.55. Not too shabby.)

jcresciSTS
07-30-09, 09:26 PM
Hmm ok I will have to check this...

Since my car is running smoother I decided to just pull the codes and reset the light and see what pops up again.

What I pulled was:
P0300-Misfire...it seems this went away, car engine seems to be running normal
P1381 - Misfire Detected - No Communication with Brake Control Module
P0171 - Fuel Trim System Lean Bank 1
P0174 - Fuel Trim System Lean Bank 2

The TCC Stuck Off didn't show up

I'll check what I get, I think I have a lead foot but nothing too tremendous. I say this because I know I have a 3000rpm shift but I'm not sure at what speed, it seems like the 1-2 shift but it may just be my acceleration. During light acceleration I can feel a shift around 16mph at around 2200.

I know when doing 65 Cruise on my RPMs are from 2200-2400, depending on slight incline.

Submariner409
07-30-09, 09:40 PM
P0171/4 is usually indicative of a vacuum leak. Trace down all the intake ducting, the throttlebody gasket, the 3 or 4 vacuum lines attached to the throttlebody casting, and the 2 larger lnes which run from near the ends of the inner faces of the cam covers: the PCV vacuum and fresh air lines. Check your oil fill cap - too much uncontrolled (PCV) air into the crankcase will set a lean code. Last, but not least, intake manifold gaskets and fuel injector lower O-rings.

A can of starter fluid (ether) with the small red tube inserted in the nozzle makes a good vacuum "sniffer": a slight shot of ether near a suspected leak will change idle speed if there's any ingested by a vacuum leak.

I have no idea how a misfire is connected with the EBCM (BCM is Body Control Module).

Ranger
07-30-09, 10:01 PM
Ok, so the RPM is SUPPOSED to increase, I thought it wasn't :(

I believe when doing 65 with Cruise my rpm's are at about 2100

Good news is I got my Coolant Exchange done and AFT Exchange at the local GM dealer, $309 total and the amazingly I benefited from these things:

Tranny feels a bit smoother when shifting and changing gear...car does go up a bit but not as jerky.

Engine is really quiet now, my lifter tick went away and so did the belt hiss.

Doesn't rough idle as bad, its a lot calmer, I'm hoping the wires will solve it completely
Correct, IF the TCC is operating correctly. Taping the brake disengages it, thus raising the RPM. No RPM increase indicates that the TCC was not engaged in the first place (as indicated by P0741).

jcresciSTS
07-30-09, 10:23 PM
Ok, well the TCC didn't show up.

The light is off now, once it returns I'll pull the codes and see what I have and go from there, regarding both the TCC and the Lean codes.