Several Problem Codes!

[MrDJ]

Hey all, yesterday as I was getting in my truck after a meeting, my check engine light was on. I took it to AutoZone to have the codes pulled and this is what I got:

p0973 (1-2 shift solenoid control circuit low voltage)
p0976 (2-3 shift solenoid control circuit low voltage)
p0787 (3-2 shift solenoid control circuit low voltage)
p2769 (torque converter clutch enable solenoid control circuit low voltage)
There was also another code but I cannot find the paperwork for it. It said the same thing as the p2769 code

They all say basically the same thing; whatever the code is referencing is registering low voltage.

My first thought might have been bad alternator with all the low voltage stuff... but my dad is leaning towards a transmission problem. Luckily my truck is still under Carmax warranty so I am taking it there this morning. I just wanted to check on here as well to see if anybody had any possible ideas.

Thanks!

 

[The_Roadie]

Yeah, could be a loose connector or ground to the tranny, or an internal problem. How many miles, and can you tell how old the battery is? Over 4-5 years and that's a red flag. How about the dash voltage gauge? Has it been reading steady or moving around?

 

[MrDJ]

Yeah, could be a loose connector or ground to the tranny, or an internal problem. How many miles, and can you tell how old the battery is? Over 4-5 years and that's a red flag. How about the dash voltage gauge? Has it been reading steady or moving around?

It has around 73,000 miles iirc. No ideas about the battery. I bought the car from Carmax about a year and a half ago; same battery.

I actually figured the problem out on my own. I put a relay in yesterday for some switches and apparently that is what caused the whole thing. After I pulled the wires out this morning, the problem stopped and the check engine light eventually went off. Now i get to diagnose the wiring I put in to see where the short is.

 

[The_Roadie]

... I put a relay in yesterday for some switches ...

Every time I neglect to ask for a complete case history, I regret it.

View attachment 19543

 

[MrDJ]

I installed 4 switches in the overhead console for various things. The first 2 go to my sound system, "to turn amps on and off..." the other 2 switches go to nothing as of yet. They are there for future expansion. All the wires go under the back seat and are terminated until they are needed. Yesterday I only had the first switch connected to one of my amps. The relay is connected to the 12v post in the rear fuse box and the signal wire comes from one of the fuses (I will check which one in a little bit). All I did was disconnect the relay and the problem went away.

Does that help?