Shift Solenoid (SS) Control Circuit Low Voltage

festerx

Original poster
Member
Jul 8, 2012
10
First thread I'm creating here so cut me some slack.

Let me start with a back story and go from there. It started 2-3 years ago; I had a lot of problems with this truck that my brother was using (he know squat about cars) that being said, he never tuned it or took care of it for that matter. When I got it from him it was in bad condition and it wouldn't accelerate that great. Then I encountered another problem, the battery would get drained in a matter of months. I changed it twice and then thought that it might be the alternator so got that brand new..turns out it wasn't that cause this is the 4th battery I've gotten and it's drained again. Another thing to take into consideration is that the regular beams wouldn't turn on anymore so I rigged it by running a wire from the fuse of the lights to the fuse of the starter so it works not but sometimes I turn off the key and the engine stays on and I have to turn off the lights to shut off the engine.


That being said, the engine lights comes on when it wants to...I took it to Autozone today and got it hooked up to the computer to determine what was wrong and it came back with the code P0976 and the description is the title of this post.

Explanation: The TCM commanded the SS on and off but the return voltage was outside expected parameters.


Is this a known issue? or can someone give me an idea of what might be causing this issue?


Note: Another thing I noticed today was when I just turn the key I heard a sparkling noise...the same noise you hear when you touch the cables together when you're going to jump a battery to see if it has some power.

It's a 2006 Trailblazer 4.2 V6

Thank you in advance
 

Sparky

Member
Dec 4, 2011
12,927
welcome.

First thing I would do is remove all rigging. Get the electrical back the way it should be first, then we can go from there. Yeah I know that headlights shouldn't have any effect on transmission BUT with the way everything is integrated these days the last thing you want when trying to do troubleshooting is one circuit backfeeding another circuit, which you have. Put it back the way it was, then we'll fix one circuit at a time.

FWIW I haven't seen that particular code come up too often. It and the battery drain could be related, potentially.

Where did the sparking sound come from? Steering column? If so, your ignition switch might be going bad. Cheap and relatively easy fix (just that steering wheel lower cover can be a pain to get lined up again). Be sure to get the gear teeth of the new switch in the same position as the old switch.

I'll let some of the more knowledgeable people help you out with the more nitty-gritty stuff but that's just a few things that come to mind. I hope they are a little bit helpful or at least a starting point.
 

McGMT

Member
Jun 17, 2012
621
I agree with sparky, the very first part of troubleshooting this problem is to remove all the engineering you have done to it so far. Then we can see what happens and diag each problem one by one. As he said these vehicles are extremely touchy, everything is linked through a common "Data Bus" which can make things CRAZY when one thing gets sick.

One thing about the shift solenoid this code is about, they are relatively cheap and easy to replace.. BUT that being said, remove your rigging and then lets start at the beginning to see what is ailing your vehicle. The lack of maintenance is really going to bite you in the ass though...


Oh, and welcome aboard....

- - - Updated - - -

I agree with sparky, the very first part of troubleshooting this problem is to remove all the engineering you have done to it so far. Then we can see what happens and diag each problem one by one. As he said these vehicles are extremely touchy, everything is linked through a common "Data Bus" which can make things CRAZY when one thing gets sick.

One thing about the shift solenoid this code is about, they are relatively cheap and easy to replace.. BUT that being said, remove your rigging and then lets start at the beginning to see what is ailing your vehicle. The lack of maintenance is really going to bite you in the ass though...


Oh, and welcome aboard....
 

festerx

Original poster
Member
Jul 8, 2012
10
Thanks for the replies...


I'd remove the wire from one fuse to the other but then the headlights won't work :-/ and I can't roll with the high beams shinning at people. Also, The spark noise was coming from under the hood, I don't know if it was from the fuse box or somewhere else under the hood.

I had a friend troubleshoot the fuse for the lights and one of them isn't getting power at all. He told me to replace the whole fuse box itself but I'm sure it will be something expensive to find especially where I live.
 

Sparky

Member
Dec 4, 2011
12,927
Common problem for the low beams not coming on is the low beam relay (#46). The fan relay is the same type (#45 right next to it), so just swap them real quick with each other and see if that fixes anything. If it does, then you just simply need to buy a new relay. MUCH more common issue than the box being bad.
 

festerx

Original poster
Member
Jul 8, 2012
10
Yeah, I saw that in a video today by Mc3 or something like that...I will try that tomorrow and hopefully it gives me something to work with from there. I'll post more tomorrow if it made a difference or not...


Thank you guys!
 

The_Roadie

Lifetime VIP Donor
Member
Nov 19, 2011
9,957
Portland, OR
There are many fuses for the lights, so it would help a lot if you could share which one your friend said didn't have power. It's a bit extreme to swap fuse boxes without a full understanding of the circuits. Many of us have the shop manuals and a bunch of experience with the circuits.

Also where exactly is your jumper wire that allows the low beams to come on? Pics would also help if it's hard to describe.

What did you fix or replace in the beginning to solve the low power issue?

How many miles do you have now?

On the battery issue, it's much more common to have an intermittent parasitic current drain than four (!) bad batteries. Has anyone troubleshot that issue with a meter? It's possible to solve these sorts of problems with structured troubleshooting, but it's a process. Changing the alternator should have done only after testing the old one or verifying it was putting out low voltage. Do you remember your meter readings at the time?
 

festerx

Original poster
Member
Jul 8, 2012
10
Here is the image of how I had it rigged from the lo beams to the ignition fuse.

http://i47.tinypic.com/986d4y.jpg


The 2nd time I noticed the power drain was when I had the alternator changed but my dumbass didn't take the one it had to get tested and once I did after the new one they told me it was a good alternator and I had no reason to switch it and I don't remember the readings. The truck has about 86-87K miles on it. Today I took off the wire I had on the fuse box and the lights were still working like they are suppose to(I wonder how long that will last). Unfortunately, the battery died after I took my lunch at work. I have no idea where the drainage is coming from and I don't want to be disconnecting and connecting the battery when I'm going to use the truck just to get around. Nobody has used a meter on the fuse box to see what's going on.

One more thing, It was the lo beam that had a pin that wasn't giving power and i believe it was the one on the passengers side which on the picture it's the top pin and the fuse on the left side in the picture is the lo beam fuse.
 

festerx

Original poster
Member
Jul 8, 2012
10
*BUMP*


Would the only way to figure out my issue to get someone with a meter and check what is still on when I turn off my truck?
 

Sparky

Member
Dec 4, 2011
12,927
What trim level is the truck?
 

Forum Statistics

Threads
23,438
Posts
639,261
Members
18,655
Latest member
Jaywebb25

Members Online