Brackets

Trying to diagnose some issues I have been having with traction control and stability system. On startup the traction control light is immediately activated and never goes out until shutdown. DIC will give "service vehicle soon" and "service stability system" warnings. Also, traction control button and cruise control are deactivated. I took the V to a local mechanic and paid to have the codes pulled as my reader is only capable of engine codes. Came back with CO163 and CO278 and I am unable to identify these codes. Any ideas? I've been searching quite a while and not having any luck. Thanks for reading.

DMM

Those are platform specific DTC's which is why they aren't defined in the code reader. You need a quality reader like Snap On or OTC. IIRC one of them is the steering wheel position sensor, which are quite common on all GM vehicles.

FuzzyLog1c

iTrader: (4)

Have you tried going to your local Autozone or Advanced Auto to rent a OBD2 reader? It's free, and should help. Also, are all of your TPMS sensors reading tire pressures that look reasonable?

chopperman69

iTrader: (-1)

I had the "service stability control system" problem on my 06 and it turned out to be a bad connector/broken wire at the right rear hub. This is the connection for ABS and traction control. The good thing is Rock Auto and AutoZone both sell a Dorman harness (970-040) with the correct plug and about 3 feet of wire for less than $40.

You might pull a wheel and take a look at the wiring.

Modis500

Year, Model, engine option, actually VIN would be most helpful, then I'll check Troubleshooter on my Modis

C0163 is a Brake Pedal position Sensor Code. Possible causes are :
Signal Circuit is Open; Brake Pedal Pos. Sensor is Faulty; BPP Sensor needs Calibration; All brake lamps open; Internal EBCM problem;

C0278 Comes up with nothing.
C0287 is a longitudinal circuit signal plausibility failure. Possible causes are: Yaw sensor faulty or in need of calibration; EBCM faulty, not sending proper signal to Yaw sensor.

2Barrel

Brackets

DMM: I believe he used a good quality reader but didn't ask or notice the brand. He is a professional mechanic though. I was really hoping for confirmation on the steering position sensor as I've read that is quite common for us.

FuzzyLog1c: I live in the Great White North so unfortunately have no access to AutoZone or Advanced Auto. But yes, all of my TMPS sensors are within range and functioning correctly.

chopperman69: I did have ABS warnings up on the dash previously until I disconnected each and every wheel speed sensor, cleaned, tightened and reconnected each connector with dielectric grease. No more warnings or lights and the ABS works so I think I can rule out any wiring issues there.

Modis500: 2005 CTS-V 5.7 LS6. Vin 1G6DN56S250130431. Mechanics code reader identified CO163 as brake switch malfunction but would give no info on CO278. Last week I took the brake switch out of the car to see if there was any way that I could adjust the sensitivity on it. Brakes lights only come on with quite a bit of pedal pressure, more than I normally use around town. I didn't turn the key on when the switch was disconnected but the battery was still connected. Could that have tripped the CO163?

Thanks everyone.

RADEoN

iTrader: (12)

Brackets, check the integrity of the ground right under the hood support. I had a few random issues like that, they ended up being related to the ground wire being worked one too many times. I ran a ground strap from that grounding location to the back of the head, and my car has been perfect ever since.

chopperman, i heard your neighbor likes CTS-V wheels. Next time you sell a set maybe you should leave them in your truck bed.

Brackets

Mine looks pretty mint but hey, it can't hurt.

Modis500

Yes, there should be a way to adjust it. Sometimes they are on a threaded rod, sometimes its the arm that is connected to the actual brake pedal arm. If not, sometimes a modified adjuster can be tacked onto, or added onto a brake pedal arm. Yeah, the lights should be turning on approximately 1/16'' to 1/8'' after it is off the switch pad. As far as the light coming on, yes, sometimes the body module will see components being replaced with key off, or it is a 2 circuit switch like in my Aurora, and it knows 1 half the switch is failing or failed.

2Barrel

Brackets

Well, I broke down and called the Cadillac dealer and spoke to the service department. They told me the CO 278 is a brake switch calibrate code. That may explain why my brake lights would only activate with what i would consider more than normal pedal pressure. It may also explain why I could find no way to adjust the brake switch. Is it the norm to do a brake calibrate after switching an ecm? I did switch mine to another one from wait4me and I have had these traction control and stability systems ever since. I've never heard of this before.

demang

iTrader: (3)

There are some charts that don't paste. If you need them pm me your email.
Thats what i got though.

C0163

DTC C0163 or C0164
Circuit Description
The brake pedal position sensor (BPP) is an input to the electronic brake control module (EBCM) . The brake pedal position sensor is a potentiometer type sensor with a 5-volt reference circuit and a low reference circuit. The BCM supplies the 5-volt reference to the BPP.

DTC Descriptors
This diagnostic procedure supports the following DTCs:
DTC C0163 ABS/TCS/Brake Switch Sensor Circuit Low
DTC C0164 ABS/TCS/Brake Switch Sensor Circuit High
Conditions for Running the DTC
DTC C0163
The ignition is ON.

DTC C0164
The vehicle speed is greater than 40 km/h (25 mph).

Conditions for Setting the DTC
DTC C0163
The brake pedal position sensor input voltage is between 1.87 volts and 5.03 volts for 2 seconds.

DTC C0164
The brake pedal position sensor input was active for 2 consecutive ignition cycles.

Action Taken When the DTC Sets
If equipped, the following actions occur:
The EBCM disables the TCS/VSES for the duration of the ignition cycle.
The Traction Control and Active Handling indicator turns ON.
The DIC displays the following messages:
Service Traction System
Service Active Handling
The ABS remains functional.
Conditions for Clearing the DTC
The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.
Diagnostic Aids
DTC C0163
Possible causes of this DTC are the following conditions:
A signal circuit of the brake pedal position sensor is open.
The BPP sensor needs calibration.
All brake lamps are open.
All brake lamp grounds are open.
An internal EBCM problem.
DTC C0164
Possible causes of this DTC are the following conditions:
The brake pedal position sensor circuit is shorted to voltage.
The brake pedal position sensor is misadjusted.
The brake pedal position sensor is stuck closed.
A brake pedal that is binding.



Test Description
The number below refers to the step number on the diagnostic table.
Test for the current state of the BPP sensor.




DTC C0278

CIRCUIT DESCRIPTION
The brake pedal position sensor is a potentiometer. The electronic brake control module (EBCM) supplies a 5-volt reference circuit and low reference circuit to the brake pedal position sensor. The brake pedal position sensor signal circuit is a direct input to the EBCM. The EBCM determines the brake pedal position based on the voltage from the brake pedal position sensor. The EBCM converts the brake pedal position sensor feed back voltage to a digital signal and puts it on the class 2 communication bus.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC C0278 Brake Pedal Position Sensor Not Calibrated

CONDITIONS FOR RUNNING THE DTC
The EBCM must be powered.
This test is run continuously.
CONDITIONS FOR SETTING THE DTC
The brake pedal position sensor calibration procedure has never been performed.
The last brake pedal position sensor calibration was unsuccessful.
ACTION TAKEN WHEN THE DTC SETS
When DTC C0278 is set the following will occur:
The engine drive control is disabled.
The panic brake assist is disabled.
The traction control system is disabled.
The vehicle stability enhancement system is disabled.
The service vehicle soon lamp will illuminate.
CONDITIONS FOR CLEARING THE DTC
The current DTC will clear when the fault is no longer present.
A history DTC clears after 100 consecutive ignition cycles in which no faults have occurred.
Clear the DTC with a scan tool.
TEST DESCRIPTION


Steps 1 - 6

The number below refers to the step number on the diagnostic table.
This step calibrates the brake position sensor.

Brackets

Thanks pard, I suppose the steps to calibrate the BPP sensor that are missing are the procedures to follow with the Tech II? Times like these I really wish I had one of those rigs.

Brackets

I'm going to swap my old ecm back in and see if the warning lights and dic messages stay off. If they do I will assume that I have to get the BPP sensor calibration done via Tech II with the new ecm in the car.

Brackets

Swapping the PCM's didn't help. While I was under there I checked the connector to the ECBM, it appeared to be good and clean so reassembled with a little dielectric grease and that didn't change anything either. I will check the connection at the DIM and RIM modules as that appears to be where our Body Control Module functions reside. Failing that I guess all I can do is take it to my friendly Cadillac service center and have the Brake Pedal Position sensor recalibrated. I'm just a little stumped as to why I would need to do this. Dead battery at some point?

Modis500

When you switched out module, recalibrations or reflashes have to be performed. This gives the modules reference points and starting/stopping points, plus inputs VIN's and tell each module which other modules are on the CAN BUS. That would explain why when you swapped in the other, the reference points would be different.

2Barrel

Brackets

So do you believe that the calibration information is stored in the PCM and not in the DIM or the RIM (as I've learned we don't really have a Body Control Module)?

Modis500

Not sure why there's no BCM, unless there's another acronym GM was using on this platform. The info would typically be in body control or a brake ctrl module. Please let me know what DIM/RIM stands for. Not close to my scanner at the moment.

Brackets

Here's a link to the thread where I was trying to find info on the Body Control Module. https://ls1tech.com/forums/cadillac-...-location.html . The best I can figure is Dash Integration Module and Rear Integration Module.

RADEoN

iTrader: (12)

Also, check out your throttle body wiring harness. It sounds out there, but trust me. I had an issue with my car where if it tried retarding the throttle plate, it would throw EBCM codes because it couldn't, as a wire was broken.

Brackets

Thanks for the tip RADEoN. I'll check it out although I'd been through all that wiring a little while ago.