cruise control doesn't work...where should i look?
Originally Posted by Hans
I have the identical cruise control system.
I went thru H*** figuring it out...first replaced all 4 lines.....the multifunction switch twice...then checked out the brake switch. It turned out to be the actuator.
Does it hold the speed at all?
check the top vaccum hose.
note my photo here. The green are the hoses that fail, the red is the actuator that failed on my 94.

We really need to know whether it tries to engage even a little bit...if it does even the slightest ammount try to hold a speed it is 98% a bad line somewhere you missed...there are many areas where a vaccum line could break.
If it does not try to engauge at all it may be a dead actuator or brake switch or multifunction switch.
I went thru H*** figuring it out...first replaced all 4 lines.....the multifunction switch twice...then checked out the brake switch. It turned out to be the actuator.
Does it hold the speed at all?
check the top vaccum hose.
note my photo here. The green are the hoses that fail, the red is the actuator that failed on my 94.

We really need to know whether it tries to engage even a little bit...if it does even the slightest ammount try to hold a speed it is 98% a bad line somewhere you missed...there are many areas where a vaccum line could break.
If it does not try to engauge at all it may be a dead actuator or brake switch or multifunction switch.
well i tried pulling up on the brake pedal while driving and the CC still doesn't operate. i also checked the far right side of the Maxifuse relay center and could only see two vacuum lines going to it (i replaced one yesterday). there was another line with a rubber elbow that ran along the firewall to the passenger side. it seemed fine & connected securely.
i think i'm just going to have to replace the control unit/actuator and see what that does...
thanks for the help!
i think i'm just going to have to replace the control unit/actuator and see what that does...
thanks for the help!
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These cars can be a PITA..... I went through a lot of crapp with mine... I even had a code for Vent solenoid... In the end it was a Vacume line.... But it was incredibly helpful having a scantool to show me that the Stalk was working as it should be as the PCM was showing I had turned the cruise on and also showd I was trying to accelerate... I knew the problem was under the hood.... I started checking vacume lines and one was collapsed... I replaced them all, no other problems untill the PCM bought the farm.... But it does help to know what the PCM is seeing...
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UPDATE
after finally taking the SSE on it'* first road trip (well, since i've owned it) i found that the cruise control actually does work.....barely :?
i've found that the switch on the turn signal stalk is functioning, and the brake pedal switch is not the culprit. the problem is is that i will set the cruise and it seems that it barely works....the pedal just doesn't go down enough to maintain the set speed. i can switch off the CC and feel the gas pedal 'let off' so it does indeed work....just doesn't pull the gas pedal down far enough to maintain set speed....so my speed gradually drops and drops.
what could this be? vacuum problem or actuator? i feel i've checked the vacuum lines enough (and replaced some of them) so i really think the actuator is the problem. what do you guys think? it sure would be nice to have working CC.
TIA
after finally taking the SSE on it'* first road trip (well, since i've owned it) i found that the cruise control actually does work.....barely :?
i've found that the switch on the turn signal stalk is functioning, and the brake pedal switch is not the culprit. the problem is is that i will set the cruise and it seems that it barely works....the pedal just doesn't go down enough to maintain the set speed. i can switch off the CC and feel the gas pedal 'let off' so it does indeed work....just doesn't pull the gas pedal down far enough to maintain set speed....so my speed gradually drops and drops.
what could this be? vacuum problem or actuator? i feel i've checked the vacuum lines enough (and replaced some of them) so i really think the actuator is the problem. what do you guys think? it sure would be nice to have working CC.
TIA
Sounds like you have been getting the vacuum off the list by replacing hoses, but you need to determine if you can rule that out and move on the the actuator. Almost sounds like the actuator is weak (low vacuum) or worn out.
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You may need to pull codes and see if you have an Vent Solenoid Malfunctions... There are several CC items that can be displayed on a scantool... My failure was a vacume line that was collapsing... Not leaking, just getting sucked flat... 
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Originally Posted by jr's3800
You may need to pull codes and see if you have an Vent Solenoid Malfunctions... There are several CC items that can be displayed on a scantool... My failure was a vacume line that was collapsing... Not leaking, just getting sucked flat... 
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On the 94-95 Bonnevilles with the OBD2 16 pin connector, you will have to use a scantool to read the codes stored in the PCM...
The same goes for the 94-95 GM cars with the 12 pin ALDL connector, as 1993 was the last year for the diagnostic pin in the ALDL connector
The 94-95 models will also have to be read via a scantool 
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The same goes for the 94-95 GM cars with the 12 pin ALDL connector, as 1993 was the last year for the diagnostic pin in the ALDL connector
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jmoline
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