Hi guys,
i have a 2006 CTS with a lot of electrical problems.

I don't have a Tech 2 for the moment so i'm trying to solve this list of problems with basic tools.

The previous owner was involved in an accident and now the car pulls some SRS codes (B0026, B0043, B0044, B0058, and U1000).
Now i'm not surprised that my SRS light is on. But that's not my problem right now.

My problem is bigger.
This is my list:

- Traction Control light constantly on (even pushing the TC button in the glove box)
- Anti Theft light comes on 95% of the times
- Temp and gas gauges don't work at all
- Backup lights don't work
- Safety gear solenoid doesn't work (the one that allows you to engage the gear by pressing the brake pedal).
- Sequential transmission works but it doesn't show the gear in the cluster
- Shifter plate backlight doesn't come on

I tried opening the car with the remote but the backup light stays off.
I tried feeding the green wire (in the trunk) with a +12V and the lights come on.
I disassembled the whole shifter assembly but i couldn't find the neutral safety switch. Later on i realized it's inside of the transmission but before opening the transmission i want to try something else.

What can i try?

Of course i've checked all the fuses, and the brake switch works ok (brake lights come on).

Anything else???

TIA

 

You really are going to need Tech2 or dealer initial diagnosis to find out what modules are working and what aren't. You also will need factory service information. You could get lucky and it a ground buss with wrecks its are hard to say. Air bags going off is like a bomb behind the dash. Force is there to protect passengers at the expense of the car.

 

I think so too but i was trying this long shot now coz it's all i have.

Any chances anybody knows where the backup light relay is?
I couldn't find it in the underhood relay box and there's nothing under the back seats

Thanks

 

It's in the rear fuse block under rear seat. It's long and narrow on drivers side has cover over it and 2 tabs to release it

 

i already removed the rear seat but there's nothing underneath. Is it possible?

 

Peel carpet forward they (2) should be mount to the front of the crossmember seat tabs lock into. Do you know where car was hit and how much damage? Backup lights are controlled by rear integration module.

Right rear fuse panel, 2005 Cadillac CTS | Caddyinfo.com Info, How-To, and Discussion

 

Ok, i have found the two fuse blocks and IGN3 fuse was blown indeed.
I replaced the fuse but nothing has changed. 10 minutes with the ignition on and the IGN3 relay gets warm, i don't know if that is normal.

I connected a TECH2 and what i was able to realize is that the shift indicator works (it tells me what gear i engage), then i activated the reverse light relay and the light turns on...

I performed a cluster swipe and everything works. But i still bave the same problems.
Actually i also checked the airbag code and it throws me a few, B0044 is one i remember, then something like B0068... btw all regarding the front deployment loop and wrong voltage about it.
I checked the front impact sensor and it was good, i did not investigate further about the airbag on the steering wheel.

So to recap:
- No reverse light on reverse
- No brake security switch on the gear (the one that prevents me to disengage the Park gear if i don't press the brake pedal
- No temp. gauge
- No water gauge
- Traction control always off (light on)
- Airbag light

The car also throws me a U1000 code.

Where do i go from here? I wish i had a schematic to understand where the different modules are to check them one by one.
However i noticed that

 

I also forgot to mention that under the pedal area it looks like something is missing (like a brake switch or brake sensor for the cruise control). Can you tell me more please?

 

Since nobody replied i went ahead with my investigations, i sp
ent the entire day on the car and i was able to understand that the previous owner did something with the immobilizer.
The reason because i say that is that all the sinthoms are the ones you have when you have an unprogrammed key (no temp and fuel gauge, TC light on, security light on) with the only difference that the car starts just fine. Now i don't know if they bypassed the positive to the fuel pump (and maybe injectors) kinda like you could have done with old VATS car or if they reprogrammed the ECM.

When i read the ECM VIN it matches the VIN of the car.
To make sure i disconnected the antenna (the theft deterrent module) and the BCM at the same time and the car started just fine.

Plus the ECM is the only module to throw me 2 different codes (U1301 and nother one for not receiving enable signal from the theft deterrent module).

Now honestly i'm lost.

The airbag light was a defective clockspring and i have fixed that. No more codes (besides U1000).


Any help? What should i check?

 

Picture does look brake switch is missing. Do you have the trouble trees to follow. I would follow U1301 breaks in serial data can cause all sorts of trouble. If PCM has been "Tuned" to bypass function I'm not sure how to diagnose thru that. If you know someone who does "tuning or data logging" they maybe able to see changes to PCM. Your other choice is trying to find a used PCM to substitute or reflash with correct programming. I wouldn't want to reflash one in car since it will run with it, after reflash it might not.