Need help with code 31

[John Larkin]

Replaced the TCC solenoid since it locked up on my Friday night. Hope it's not in the ECM itself. I touched the old TCC to the battery terminals to see if it would energize and it sparked. Reinstalled everything and all checked out to spec. Now a code 31 sets after I am in 4th gear and is popping the ECM/SOL fuse. I had to replace the 4th gear pressure switch too since I broke the tip off it.

Also the Cig/Clk fuse is popping the minute I replace it. I guess the only way to figure this out is 2 things:

1. Check every accessory for continuity from the Cig/Clk fuse and see if there are any wires shorting to ground.

2. Check continuity from the brake switch through the trans plug and see whats up there.

I'm really at a loss since the gnttype diagrams are darn hard to read. Any help appreciated. I did a search on code 31 and found claims of pinched wires, etc.

Guess I'll start with the Cig/Clk fuse since it should be unrelated.

 

[John Larkin]

Update: unplugging the trans plug has stopped the ECM/SOL fuse from popping so I know I have a problem there. I now have A/C too so this isolates this problem.

However, the Cig/Clk fuse is still a mystery.

 

[TurboJim]

Originally posted by John Larkin
Update: unplugging the trans plug has stopped the ECM/SOL fuse from popping so I know I have a problem there. I now have A/C too so this isolates this problem.

However, the Cig/Clk fuse is still a mystery.

Well, ECM/SOL is what powers the WG solenoid (Code 31) and if the car was an 88 or 89 it wouldnt have shown up as a QDM fault...

Anyway, it sounds like the TCC solenoid is in wrong, and/or a wire is pinched somewhere.

As for the Ctsy, hard to say. Do you have a cell phone plugged into the lighter? Maybe the plug thingy is NG?

 

[John Larkin]

Thanks Jim. With help from Martone, found the lighting problem. Burnt wire above the dome light and a bad ground for the rearview mirror map lights. Fixed that and all is well on that end.

Here's what I know about the TCC:

1. I have continuity from all the wires on the trans plug to the ECM on their appropriate pins (except the purple wire of course).
2. The brake switch operates properly.
3. With the TCC unplugged, the ECM/SOL fuse doesn't pop.
4. When testing, I will get the car up to 55 and the code 31 sets, also popping the ECM/SOL fuse with the harness plugged in. Never tries to go into lockup.
5. The ground wire for the TCC shows 0.3 ohms to ground. I'd say this is ok.

I took a resistance reading across the solenoid at the plug and got 2 ohms. I tested the old one that locked up on me Friday night and got 8 ohms. I'd say the new one is at least better than the old one.

Bruce thinks it may be a pinched wire from the original converter installation. It may be but I'm tired from working on the lights all day. The trans has been intermittent in locking up; sometimes it would, sometimes it wouldn't. Not sure if that would indicate a pinched wire or a faulty solenoid altogether. I'll deal with that later in the week.

Again, thanks for the suggestions!

 

[TurboJim]

Originally posted by John Larkin
3. With the TCC unplugged, the ECM/SOL fuse doesn't pop.

Telling you its DEFINATELY on the POWER side of the TCC solenoid, IN the trans...

4. When testing, I will get the car up to 55 and the code 31 sets, also popping the ECM/SOL fuse with the harness plugged in. Never tries to go into lockup.
5. The ground wire for the TCC shows 0.3 ohms to ground. I'd say this is ok.

Well, again, it doesnt blow with the trans unplugged, I bet you $ you pinched a wire in there and its grounding. Or the solenoid is bad. Which would explain the blowing at 55, my chip locks at 47 (I just looked) and it might take 2-3 secs to get to 55 where the TCC solenoid might overheat and cause a direct short.

I took a resistance reading across the solenoid at the plug and got 2 ohms. I tested the old one that locked up on me Friday night and got 8 ohms. I'd say the new one is at least better than the old one.

Not necessarily. I forget offhand the resistances, but I seem to remember 9-12ohms being the norm for most solenoids, 2.5 or so for injectors.

Bruce thinks it may be a pinched wire from the original converter installation. It may be but I'm tired from working on the lights all day. The trans has been intermittent in locking up; sometimes it would, sometimes it wouldn't. Not sure if that would indicate a pinched wire or a faulty solenoid altogether. I'll deal with that later in the week.

Again, thanks for the suggestions!

I agree with Bruce, I'd go for a Dexron shampoo and check those wires.

 

[John Larkin]

I've pretty much resigned myself to another pan drop. Maybe it'll be less painful in a few days. Thanks again!

 

[MeanBuicks]

The TCC solenoid should measure 24-26 ohms. Sounds like there's a definite problem in there.

 

[John Larkin]

I must have been drunk on fumes yesterday. Here are the resistance readings I got after removing the new solenoid and comparing to the old one.

New one = 20.0 ohms
Old one = 0.0 ohms

I tested the new one and it clicked when power is applied. The plunger only moves about 1/16" though at the bottom. Does this sound about right? I guess I'll reinstall and then recheck the readings at the plug. I didn't notice any wires in a bind but maybe my soldering job wasn't up to par when connecting the wires.

 

[John Larkin]

Yay, finally fixed. I don't know what I did, but I was very methodical in reinstalling everything. I'm guessing it was my soldering job on the wires going to the new solenoid. Locks up just like new. Thanks for the hints everyone.

 

[TURBOV6]

Originally posted by John Larkin
However, the Cig/Clk fuse is still a mystery.

I had many problems with Monte/Regal's with the cig. lighter going bad, many eventually shorts out if you smoke and use it alot. Try to remove the radio trim and unplug the cig. lighter.