Will a 4t60E Variable Speed Sensor stop Cruise Control From working?

[shrewz92]

1997 LeSabre Custom. No Cruise Control.
I've replaced Brake Switch and the switch above the brake switch, and checked the control box cable (the yellow one inside the control unit), and still have no cruise control on the LeSabre.

One forum thread here suggested that some Transmission issues could be tied to the Variable Speed Sensor (dropping out of Overdrive to 3rd), since all that ties together.

Does the VSS have any influence on the Cruise Control activation?

 

[2007LucerneCXL]

Not sure if this was a items you checked but it may be something to consider it's the cruise control module #8. Other than checking the connection I'm not sure how to check it without a professional scan tool.

 

[MelsRegal]

VSS=Vehicle Speed Sensor

 

[imidazol97]

I assume you have the two switches activated by the brake pedal properly adjusted...

This is a long memory recall and I haven't tried to look it up but is the cruise control
turned off if the brake light bulbs in the rear window brake lights are burned out?

And I believe there's a temperature connection for turning on the cruise control,
maybe the transmission temperature--somewhat like that temperature can keep the
trans from locking up the converter until the trans fluid is warm enough in severe cold
winter temps.

Does anyone have a 1997 FSM?

 

[BuickGirlFromMars]

there are only three inputs to disable cruise by the driver:
depress pedal,
when ignition switch off
cruise switch off

There are some PCM inputs to disable cruise regardless of your input::
engine is off,
Trans is in park, neutral, low, or reverse,
Engine speed is too high
Vehicle speed is too high
Vehicle acceleration or decelleration is too high
Antilock or Traction active for more than 2 seconds

There should be a dark green wire to the module underhood(forgive me if not) the PCM disables cruise by GROUNDING that wire. I would look for short on that wire.

Also, check your brake release switch adjustment, im not sure on the spec for a 97 lesabre, but its got to be gapped properly.cruise linkage also has adjustment

 

[BuickGirlFromMars]

very similar system.. for a 99 park avenue, so its why the things i said in last post were more generalized/non specific.. do care to use this as a guide for helpful ways to look at issues, not definitivie

 

[shrewz92]

I have looked for breaks in wiring at cruise module and found none. Connections at, and, to the module are tight and clean. I disconnected the throttle cabling at the module to inspect the yellow strap inside and found it strong and intact and connected, internally. I need to apply a multimeter to check for power/continuity. I am sure that the two switches on the brake pedal are set correctly, per Haynes manual, but will recheck. As imidazol97 noted, above, I also did a repair to the high brake light socket in September, replacing the socket and bulb to no effect on cruise.

I will also look for short on green wire, suggested in #5.

Regarding the VSS signal, scanner reads +3 mph above display on speedometer. At one point, speedometer read at 71 mph, when scanner live-data showed 75. Is that typical for GM for this model, or, does VSS need replaced? It seems an easy bolt-in.

 

[shrewz92]

Is the lower switch, at the pedal,stop lamp and cruise related? Is the upper switch cruise control related, or relatives d to antilock brakes?

 

[BuickGirlFromMars]

I have looked for breaks in wiring at cruise module and found none. Connections at, and, to the module are tight and clean. I disconnected the throttle cabling at the module to inspect the yellow strap inside and found it strong and intact and connected, internally. I need to apply a multimeter to check for power/continuity. I am sure that the two switches on the brake pedal are set correctly, per Haynes manual, but will recheck. As imidazol97 noted, above, I also did a repair to the high brake light socket in September, replacing the socket and bulb to no effect on cruise.

I will also look for short on green wire, suggested in #5.

Regarding the VSS signal, scanner reads +3 mph above display on speedometer. At one point, speedometer read at 71 mph, when scanner live-data showed 75. Is that typical for GM for this model, or, does VSS need replaced? It seems an easy bolt-in.

stock tire size and proper PSI? I would check your wheel speed singnals for their speed AT the samr time as your vss. if you see a varianced, I could see that not being bueno with the PCM. My 1999 park avenue has at most a 1mph variance at the proper tire/inflation and usually is just half a mph off the scanner/speedo. 3 seems high, iirc the 1999 park avenue speedo has a +/-2 accuracy on the gauge cluster but i could be wrong

 

[shrewz92]

Yes, correct tire size and pressure, possibly 32, as opposed to 30 on the b-pillar sticker. I am emphatic about pressures being at, but not below, sticker pressure, and regular maintenance checks done at each fuel stop.

How does one check the wheel speed signals at same time as vss? Is that done via a super-scanner? I was on freeway, live data streaming my speed, while I eye-balled the speedo.

 

[BuickGirlFromMars]

a scanner capable of reading Chasis codes for EBTCM on the Delco/Bosch 5.0 ABS system on UART protocal(not class 2 serial bus, not sure how it connects)