[last Saab]

1999 9-3 AUTOMATIC with 205,000 miles.

Using the stalk, the cruise control light doesn't come on. Fuse at left side of dash (#22) is good. Both switches at brake pedal are good (they look good and I tested them both with a multimeter). I switched out the stalk with a junkyard find, and still no cruise control light.

I'm left thinking faulty cruise control module. If not that, a faulty ABS module (my brakes sometimes bottom out towards the end of a slow speed stop, as if they're ready to start that ABS 'pulsing'). The speedometer works, so I don't have a wheel speed sensor problem.

Any other ideas? I'll be at the junkyard this weekend to take advantage of a 50% off sale. Would it be worth pulling a control module, just to rule it out? Pulling another stalk?

By the way, the last time I used the cruise control it suddenly cut out. The stalk 'clicked' like when you push it to the right to cancel it, and that was it.

Thanks for your help.

 

[BLACKFXGT]

Most likely a bad ABS module. I had same symptoms as you when mine went. Find someone near you with a scanner that can check it. Mine wasn't communicating with the ECU. Also ABS light never illuminated on the dash.

 

[last Saab]

I went to the yard today and pulled a ABS module from a '97 900S. Installed it and no change to anything. Speedometer still works, ABS light doesn't come on, so I assume the module works. But I have no cruise control.

I have a feeling there wasn't anything wrong with my original ABS control module.

That leaves the cruise control module as the last likely cause. Does anyone know if these go bad sometimes?

 

[BobSaabit]

I think I've only seen a couple reports of bad CC modules in 15 years of ng900 (t5) ownership.

 

[last Saab]

Yeah, the cruise control modules haven't really turned up on the forums as being problematic.

My local independent SAAB guru thought the problem could be in the instrument cluster. Beyond a burnt bulb, I don't see what the instrument cluster has to do with the lack of cruise control.

Here, someone discovered that it was the throttle body: http://www.saabcentral.com/forums/showthread.php?t=309306

I don't have any performance issues at idle, or while accelerating, or while cruising.

 

[BobSaabit]

That post is for a T7. You have to be careful to differentiate. The T7 is "throttle by wire". There is no physical connection between a T7 throttle cable and the throttle plate under normal operating conditions. The ECU always calculates the engine and throttle parameters needed for the speed/torque requested and adjusts the throttle through the throttle body control solenoid. When cruise control is used, it just adds in measuring the speed requested and does the usual electronic adjustment.

The T5 that you have uses a control unit in the engine compartment. It has a cable that physically pulls the throttle to the position needed for the selected speed. I don't know whether the logic part of it (measuring speed, adjusting position) is in the ECU or the control unit.

EDIT: In case you are unfamiliar... the ng900 and '99 9-3 had the T5 motor. Starting in 2000, the 9-3 got the T7 motor. Applies to USA only, cutover in other locals varied. Viggen is always a T7.

 

[last Saab]

I just changed out the cruise control module with one I got off of ebay (someone was parting out a '99 9-3), and am happy to report that the cruise control now works.

 

[hapcj7]

Did you try adjusting the CC switch down by the brake pedal?..I know you say you testing it, but that needs to be adjusted properly...When i bought my car years ago, that was "my" issue..