1997 Volvo Cruise Control won't engage

[chief916]

Hope some of you folks that have been around for awhile and have traded up over the time you've been over the road can pass on some knowledge about the cruise control system on the early model Volvo's.  When I am parked and the service brake is applied...I can turn the cruise switch on and can bump the motor up to a high idol.  When going down the road I can't get the cruise engaged,  My buddy who I hang with and works on the big stuff put his Snap-on puter onto the truck and it said that the cruise was off.  He went through the whole system with a test light checking all the pressure switches and the only thing He found was a pressure switch behind the brake valve panel that kept releasing air.....the bottom plug on  the sensor was missing.  I ordered a new one and put it in but still can't get the cruise to engage.  My question is this,,,,,if you get a check engine lite on for a battery in the ecm but don't correct the fault does the bad switch also throw a fault and if you don't clear the fault after you replace the switch...will the ecm override the replaced switch by not engaging???  Do I need to clear the faults to get the cruise to engage?  Sure would appreciate knowledge out there from you guys.

OBTW.....I just happened to mentioned the Kansas rally to the DW and she said if we can get some of these issues ironed out on the truck she would feel better bout making the run.  as it is now...we're making a run for Charleston on Saturday for the eclipse.  good thing is..its only 5 hours from the house and I believe I can dead stick it in to there from here.  Will put a post in after we get there.  Thanks for your help. 

[Wrknrvr]

What engine do you have.

 

 

 

That would help for info.   Vern

[chief916]

Series 60 Detroit 11.1

It's real slow starting out but by 6th gear she rolls up rapidly to 9th.

[Brad & Jacolyn]

If the cruise will not engage the first thing I would try is to lift the brake pedal with my toe and try to engage the cruise then. If that works it is an adjustment of the pedal (I forget what the switch is but if the pedal is to low the cruise will not engage). I had that problem and I put a small bungie cord around the pedal to hold it up until the adjustment can be made. Just a possibility.

 

Brad  

[Pete Kildow]

I agree check the switches on the Clutch and brake peddle. And if you have jakes they should not work also. Being there tied into the curse. Can you still use the high idle? Set the cruse and bump down on the set switch. And you should still have high idle.

If its not the switches, but 95% of the time its one of those. Some times it can be the jake brake wiring harness. Where it goes into the valve cover. 

If your getting the fault for the batter in the ECM. There's a guy that can replace those. But most times, people just get a rebuilt ECM. Is it the DDEC-3 or 4?

Pete

Edited August 18, 2017 by Pete Kildow

[Star Dreamer]

We have Freightliner with a series 60 engine so it may or may not be the same. We have a separate cruise on/off switch and a set/resume switch. Each time we start the truck I have to turn off the on/off switch and then turn it back on before the set speed switch will lock in the cruise, even if the light is on for the cruise by the on/off switch.

Dave

[chief916]

On 8/17/2017 at 7:09 PM, Brad & Jacolyn said:

If the cruise will not engage the first thing I would try is to lift the brake pedal with my toe and try to engage the cruise then. If that works it is an adjustment of the pedal (I forget what the switch is but if the pedal is to low the cruise will not engage). I had that problem and I put a small bungie cord around the pedal to hold it up until the adjustment can be made. Just a possibility.

 

Brad  

 

On 8/17/2017 at 8:22 PM, Pete Kildow said:

I agree check the switches on the Clutch and brake peddle. And if you have jakes they should not work also. Being there tied into the curse. Can you still use the high idle? Set the cruse and bump down on the set switch. And you should still have high idle.

If its not the switches, but 95% of the time its one of those. Some times it can be the jake brake wiring harness. Where it goes into the valve cover. 

If your getting the fault for the batter in the ECM. There's a guy that can replace those. But most times, people just get a rebuilt ECM. Is it the DDEC-3 or 4?

Pete

 

On 8/17/2017 at 7:09 PM, Brad & Jacolyn said:

If the cruise will not engage the first thing I would try is to lift the brake pedal with my toe and try to engage the cruise then. If that works it is an adjustment of the pedal (I forget what the switch is but if the pedal is to low the cruise will not engage). I had that problem and I put a small bungie cord around the pedal to hold it up until the adjustment can be made. Just a possibility.

 

Brad  

Here is a couple of threads from August 17, 2017 about my ecm going bad.  Hope it helps.

Chief916

[Exile]

Thanks, my jakes do work, so might be a bad ecm

[chief916]

16 hours ago, Exile said:

Thanks, my jakes do work, so might be a bad ecm

I don't have a Jake but now with the new ecm I leave the cruise switch in the on position even when I shut the rig down.....I forget to turn it off.  But when I start things up the cruise is on but not engaged.  I just set it when I get up to speed.

[chief916]

So sorry everyone.... don't know what I did to start this thread....I was trying to share info on what I went through on the gentleman who had the cruise problem in the...I believe it was a Pete.  There was a lot of good info in there but it didn't work out for me.  I ended up hthis aving the Detroit people fixing it.  Again so sorry for this posting screw up.

Chief916

[rickeieio]

38 minutes ago, chief916 said:

Again so sorry for this posting screw up.

Just wait.  It'll get worse when you get old.....er.😉

[chief916]

22 hours ago, rickeieio said:

Just wait.  It'll get worse when you get old.....er.😉

😂

[Pete Kildow]

Fixed my Cruise today. Yes filled up all 4 fuel tanks. So with all 470 gallons of tanks full. The stinking cruise went to working perfect. LOL So guess it was just mad to only have 65 gallons of fuel.

[lappir]

On 5/24/2020 at 10:33 AM, Pete Kildow said:

Fixed my Cruise today. Yes filled up all 4 fuel tanks. So with all 470 gallons of tanks full. The stinking cruise went to working perfect. LOL So guess it was just mad to only have 65 gallons of fuel.

My first trip pulling my trailer with my Volvo and the cruise control wouldn't work. My brother had driven the truck to Florida for me and was right behind me. We had radio's to communicate and I asked him if it had worked on the trip. He said you have to apply the brakes before the cruise control will work. Since starting the trip I had not had to apply the brake, hit all the lights and was on the freeway in nothing flat. I pressed lightly on the brake pedal and nothing. I quickly stabbed the pedal hard and then hit the cruise and success.  I now try to stop once before I head on the interstate so I'm not hitting the brake at 70 because the cruise won't engage.  Didn't see anyone above share the fact. 

 

Rod

[Imurphy907]

On 6/24/2020 at 2:57 AM, lappir said:

My first trip pulling my trailer with my Volvo and the cruise control wouldn't work. My brother had driven the truck to Florida for me and was right behind me. We had radio's to communicate and I asked him if it had worked on the trip. He said you have to apply the brakes before the cruise control will work. Since starting the trip I had not had to apply the brake, hit all the lights and was on the freeway in nothing flat. I pressed lightly on the brake pedal and nothing. I quickly stabbed the pedal hard and then hit the cruise and success.  I now try to stop once before I head on the interstate so I'm not hitting the brake at 70 because the cruise won't engage.  Didn't see anyone above share the fact. 

 

Rod

My 2001 660 with a Cummins and 10 speed does not require I step on the brake. I had never heard that before.

But you do have to make sure you don't rest your foot on the clutch or brake pedal as my wife learned...

[Dennis M]

On 6/24/2020 at 3:57 AM, lappir said:

My first trip pulling my trailer with my Volvo and the cruise control wouldn't work. My brother had driven the truck to Florida for me and was right behind me. We had radio's to communicate and I asked him if it had worked on the trip. He said you have to apply the brakes before the cruise control will work. Since starting the trip I had not had to apply the brake, hit all the lights and was on the freeway in nothing flat. I pressed lightly on the brake pedal and nothing. I quickly stabbed the pedal hard and then hit the cruise and success.  I now try to stop once before I head on the interstate so I'm not hitting the brake at 70 because the cruise won't engage.  Didn't see anyone above share the fact. 

 

Rod

Yup, same thing on my '99 Volvo. In fact, the operating info on the sun visor spells it out. As I recall it actually says to apply the service brake for 15 seconds after start to "activate" the cruise control. I can't count the number of times I have rolled out of rest area without hitting the brakes and then no cruise.

[usbusin]

What is the purpose of this procedure? How is it safety related or? Is there any way to bypass this?

[Scrap]

Safety & liability.  Official term is "Cruise Control Rationality".  The 3psi and 60 psi pressure switches use the same housing, but you really don't want to screw them up or lose a ground or something.  Nowadays the truck can tell you to hit the brake or clutch in the dash display, but back then there wasn't really one.  Usually it'll set a code in the cab controller when its stuck on rationality, and/or has a 1939 message that can be read.  Can you add an indicator to your Silverleafs or Bluefire screens to display rationality status?  I don't remember it being a 90's thing, and not really a thing till 2004/2005, but maybe it was a Volvo thing way earlier.