cruse control--Air Horn

[Bobby Kirk]

I have a 2006 Beaver Marquis  Cruse does not go off when brakes applied  Have to turn off manuly and the air horn does not work. Is my problem likely in the Smart Wheel?? Thanks for the help  Love the Forum.

Bobby Kirk

[Steve Huber Co-Admin]

Bobby,
Could be. Is your CC programmed to go off when the exhaust brake is applied? If so does that function work? I think  there is a connector on the steering post that comes from the smart wheel. Check that and maybe hit it with contact cleaner before pulling the smart wheel apart.
Steve

[Eric Maclean]

Bobby
I believe the cc has a relay tied into the brake lights via relay which interrupts the cc circuit when the brakes or exhaust brake are activated.
The first thing to check would be the brake lights.

Eric

[Bobby Kirk]

Thanks for the help.  Brake lights work. When I rev engine up and set cc jake brake does not turn it off and neither does break
pedal  When I hold resume button down the check engine light comes on and blinks 5 times twice without cc being on. When cc
is on hold down resume button and engine reves up untill you release butrton.  Hear clicking from horn but no noise..Thanks

[Eric Maclean]

Bobby
The cc bottoms can be used to set a fast idle if you have the cc turned on and hold the resume Boston the rpm should start to raise it should stay at the point where you let off on the resume bottom and should drop back to base Idle if you tap the brake .
The cruise control is accomplished through the Cat ECM and is requested and cancelled by relays which are inturn controlled by the Smart wheel
The fact that you can't get the cc to shut down points to the cc cancel relay K5 or a bad connection to it in the rear.pcb ( Printed circuit board )
If the brake lights are working then the F2 fuse must be ok and the relay is controlled by the brake !ight circuit
The 2007 Patriot/ Marquis wiring diagrams in coach assist my help you trouble shoot the problem.
Look at page 175 for the Smart wheel wiring and note The K5 relay which is the  cruise control cancel relay it should receive a signal from the brake light circuit which will activate the K5 relay and interrupt the cruise circuit.
On page 193 is the wiring diagram for the rear lighting including the brake light circuit unfortunately it does not show the cruise cancel relay in the diagram.
In the 2006 Monterey wiring diagrams on page 4 it shows a better schematic but there they are designating the cruise cancel relay as K4 either way I'd look at the relays in the rear run compartment and maybe try swapping an known good relay in to the K4 or K5 and see if you regain your cancel operation.

Hope this helps and
Good luck
Eric

[Scott Shearer]

Bobby,
 
Inop horn:
The click you are hearing when pressing the horn button is probably the air horn relay or the air solenoid valve. See if you can determine the origin of the ‘click’.

The air horn relay is located on PCB #8 in the front run bay, the air solenoid valve is located on front firewall, passenger side.

If the relay is clicking and the solenoid is not, check for 12 volts at the solenoid. If there is power at the air solenoid, then the solenoid is likely the problem. If there is no power at the air solenoid, then check the relay (on PCB #8) and examine the wires and connections between the air solenoid valve and the front run box.

I’ve attached an image of PCB #8 and the air solenoid valve.


Cruise cancel:
The cruise control cancel on your 2006 Marquis should be like that on our 2006 Patriot Thunder. You can verify this by running your generator slide out, from the driver's, side look high up on the firewall and slightly off center towards the right (facing the firewall). If you see something like that in the attached image (Presure_Switches-01), then our systems are alike, otherwise ignore the rest of this post.

The brake light circuit and the cruise cancel are controlled by separate pressure switches. In total, there are four pressure switches incorporated in the redundant braking system, two for the brake light circuit (normally open) and two for the cruise cancel (normally closed).

Applying the service brakes pressurizes the four switches causing the NO (normally open) switches to close and the NC (normally closed) switches to open. The ’closed’ NO switches will activate the brake light relay and the ‘open’ NC switches will cancel the cruise control.

You can perform a quick test by starting the engine, use the cruise to place it in fast idle. Then, pull one of the leads off the normally closed switches.

If the cruise cancels and the engine drops to normal idle, then the cancel circuit is good, and you’ll need to test to BOTH of the normally closed switches.

Remove all the leads from both normally closed switches and verify continuity between the terminals.
-with the service brakes released, the contacts should be closed (full continuity)
-with the service brakes applied, the contacts should be open (no continuity).
If the contacts do not open, the switch is bad and will need to be replaced.

While it would require both normally closed switches to be faulty to prevent cruise cancel. It is possible that one switch has been bad for a while with the other failing more recent.

If the cruise did not cancel in the above test, then the cancel circuit is the issue.
Shorted or compromised leads to the normally closed switches can cause the cruise cancel to be inop.

-Scott