tcs ctrl failure [Archive] - SaabCentral Forums

: tcs ctrl failure

4th November 2002, 06:13 AM

My 1993 Saab 9000 CSE Turbo is having some difficulties and I wondered if there are Saab-drivers that suffer from the same problem. This is the case:

From time to time the TCS CTRL light switches on. The engine power is cut in half (engine switches off when cold), the throttle handles very heavily, brakes seem to be slightly activated en cruise control fails. This should be the reaction to wheel spin, but if that is so, it shoud also be turned off automatically and it doesn't.

You can reset this failure by switching off the engine a few times at a speed of approximately 80 km/h. Does anyone know how to fix this problem permanently?

greetz, Erik (Holland)

6th November 2002, 03:39 AM
Hello Erik,

Things that can go wrong......

Relay or tcs module(failure in this is usually
accompanied by leakage out of the hyrdaulic spool valves at the bottom of the module) this is expensive!


6th November 2002, 03:57 AM
Hi, Erik. Welcome to SaabCentral.

A common failure is the TCS safety valve. Replacement is the cure. Another possibility, especially if the car hasn't been maintained by a Saab dealer, is a dirty throttle plate. Because TCS uses a "drive by wire" throttle, a buildup of dirt on the throttle plate which causes it to stick or to react slowly means that the throttle plate isn't always where the system tells it to be.

For almost any TCS failure, since it is dangerous for a malfunctioning system to be controlling your throttle, the system "fails safe" and goes into "limp-home" mode. This mode is what you are describing.

Cleaning the throttle body is a scheduled item at every service, but many non-Saab garages don't know about it.

I also had "limp-home" mode on my 1990 9000CD. It turned out to be a faulty accelerator pedal sensor. However, that car would usually fail while coming to a stop. It did do it a few times while driving along, when I backed off the throttle, and turning the ignition off and back on cleared for a while.

Other than those simple items, the throttle body can fail in other ways, and it is expensive to replace.

Matt Phelps
6th November 2002, 08:14 AM
Which models don't have traction ctrl? Would I have it on my K reg 2.3i? I don't think so because I'm easily able to spin the wheels in the wet.

6th November 2002, 12:25 PM
I think you've answered your own question :wink:
I believe it was only available on 2.3 full-pressure turbo models. i.e. the 200hp engines and the 225hp Aero engine. It wasn't even on all of those, since it was only standard for a couple of years, then became optional for a couple of years, and was finally dropped altogether.

The 3.0 V6, I believe, all had TCS. However, the TCS on that engine worked differently and didn't have the "drive-by-wire" throttle. This meant that most TCS failures didn't affect the running of the car, just the TCS function.

20th November 2002, 09:38 AM
What a coincidence. I also have a '93 9000CSE turbo which recently had the TCS CTRl light come on with the same failure. The problem resolved itself by restarting the engine. It hasn't happened since. The 'check engine' light came on though, and blinks one long, five short blinks before the car is started. One addition bit of info. For the last few months, the TCS CTRL, BRAKE FLUID and ANTI LOCK warning lights are taking longer to go out (20-30 sec) when the car is started in the morning, but not the rest of the day. All the lights go off together. Is this a single problem? Is the TCS safety valve, TCS module and relay the same part? Where is the module located to check for fluid on the bottom of it? Thanks for any advice. Rob D