Problems with ABS and traction warning light

[Jonny Wallin]

Hi!

I hope that someone can help me think logical on all of my error codes.

Have had a STS -99 since February that have had the same failure all the time. Occasionally ABS and traction lights up.

When these are lighted I get this additional fails:

Steering hard

Automatic deactivation of handbrake out of function

Heated seat out of function

Climate system doesn't work

and of cause not ABS & Traction the function.

etc.

Have now learned me that this is normally as long as the ABS and traction light shines.

When these turn off after 10-20 minutes it works, and the entire car works normally again.

The car have been to workshop called Klintberg & Way (Swedish Car) 5-6 times but they manages not out the failure.

They have been made an exchange of ABS unit complete with new computer.

They have change out computer box for suspension system.

They have mounted temporary cables between the computers in order to exclude cable failure etc.

New battery. All ground points is cleaned and fixed.

New fuses in both fuse boxes.

The error is still there. But the car can work for 3-7 days without error codes.

I have give up Klintberg & Way dealer.

I have read on the American Cadillac forum that any (or several) change ignition connector-block and the problem has gone away. Can that be a solution?

My error codes is the following:

IPC 1040C

PCM P1602C

SDM U1040C

RSS 1780C thinks that this is a following failure from codes above.

RSS 1783C

RSS 1785C

IPC U1255 thinks that this is a following failure from codes above.

IPC C1780C

Occasionally comes also these codes:

1644

1225

1611

For me it’s confusing with all this codes. But I know that some of you can give me some ideas.

I think that this is a challenge for me to try to solve the problem myself with some help from you. I don’t want to give up a wonderful car to drive and own.

Hope on help. (This became a long article, sorry)

Regards

Jonny Wallin in Sweden.

[JimD]

It sounds like you are displaying your trouble codes on the DIC.

Some of the codes you reported are not making sense. A Diagnostic Trouble Code for your year model takes the form of one letter followed by four numbers such as C1234. The letters used are

B for Body

C for Chassis

P for Powertrain

U for Network

There is also a three letter module designation included (such as IPC or RSS) but the module designation is not important information because the code itself is very specific.

Here is what I would do in your case.

Clear all the existing codes. Test drive the car. The moment you see an ABS or TRACTION CONTROL message on the DIC, pull off the road and display and note the trouble codes.

I suspect you will see one or more "C" codes displayed.

[Jonny Wallin]

Thanks for fast answer.

I will try that during tomorrow. Now it´s close to midnight in Sweden.

[Jonny Wallin]

Hi again!

I have been driving for 45 minutes today but without any failure. New try tomorrow.

How can I step one code after the other? It´s now difficult to read and write at the same time.

Regards Jonny Wallin

[JimD]

Hi again!

I have been driving for 45 minutes today but without any failure. New try tomorrow.

Now that is good news.

How can I step one code after the other? It´s now difficult to read and write at the same time.

Read the instructions for stepping manually through your codes on this page

http://www.caddyinfo.com/readingcodes.html

[Jonny Wallin]

Hi again!

I have been driving for 45 minutes today but without any failure. New try tomorrow.

Now that is good news.

How can I step one code after the other? It´s now difficult to read and write at the same time.

Read the instructions for stepping manually through your codes on this page

http://www.caddyinfo.com/readingcodes.html

Okay Jim D.

Today the control lamps light up and I directly checked the error codes and found:

ICU 1255 Current

PCM 1602 Current

SDM 1255 Current

And after 10 minutes the lamps disappear. I reset all codes and drive 100 km and check again when I came home and no error codes at all.

The problem is worse i early mornings when the car is cold.

Do you have any idea about the failure?

Regards Jonny Wallin

[JimD]

I'm going to assume you mean C1255.

C1255 - EBCM Internal Malfunction

Now, that "might" mean the Electronic Brake Control Module has failed, but that is rare. And you did mention the problem seems to be temperature related. I would carefully inspect the electrical connector and associated wiring looking for obvious damage and connector pin corrosion. The EBCM is located at the bottom left front corner of the engine cradle; there are six steel brake lines attached.

When C1255 is present, your ABS, Traction Control, and Stabilitrak systems are disabled.

The ABS indicator is turned ON.

The TRACTION CONTROL indicator is turned ON.

The SERVICE STABILITY SYS message is displayed.

I'm also assuming you mean P1602.

P1602 - Loss of EBTCM Serial Data

This is related to the C1255 code above (GM does not use the same abbreviation the same modules in every case; EBCM and EBTCM are the same module.

Happy hunting.

[Jonny Wallin]

I'm going to assume you mean C1255.

C1255 - EBCM Internal Malfunction

Now, that "might" mean the Electronic Brake Control Module has failed, but that is rare. And you did mention the problem seems to be temperature related. I would carefully inspect the electrical connector and associated wiring looking for obvious damage and connector pin corrosion. The EBCM is located at the bottom left front corner of the engine cradle; there are six steel brake lines attached.

When C1255 is present, your ABS, Traction Control, and Stabilitrak systems are disabled.

The ABS indicator is turned ON.

The TRACTION CONTROL indicator is turned ON.

The SERVICE STABILITY SYS message is displayed.

I'm also assuming you mean P1602.

P1602 - Loss of EBTCM Serial Data

This is related to the C1255 code above (GM does not use the same abbreviation the same modules in every case; EBCM and EBTCM are the same module.

Happy hunting.

Hi again!

My problem is that the whole ABS equipment including the data module is changed to a brand new one. All connectors look like new. I´m suspicious about ground failure for the ABS unit. I thought that I have fond them all. But where´s the ground point for ABS unit?

Can it be the ignition connector?

Regards Jonny Wallin

[JimD]

Hi again!

My problem is that the whole ABS equipment including the data module is changed to a brand new one.

In my mind this fact points directly at a vehicle wiring harness - connector problem.

All connectors look like new. I´m suspicious about ground failure for the ABS unit. I thought that I have fond them all. But where´s the ground point for ABS unit?

There are chassis ground points throughout the car. And most of them serve more than one system. Since you have codes for only the brake control module, I would spend my effort looking for a faulty module connector or a broken wire within a wire bundle. A broken (open) wire can be impossible to "see" because of the insulation, but you can usually "feel" a break in the conductor.