Engine brake non functional on a 2003 Patriot Thunder

[Will Braswell]

Hello to all. I’m a new member so I’m still feeling my way around here so forgive me if this subject has been covered before. I have a 2003 Patriot thunder C-12/ Allison 4000 that is 40’ with tag axel. My problem is I cant get the engine brake to function while on the road. The CAT dealer had it working by connecting his computer and over riding the cause of the problem, but it doesn’t point to the underlying issue. We know it’s not a mechanical issue as it functioned on both the high low setting While connected to computer but something keeps preventing its normal function.
Any help would be appreciated. Please note this rig is new to me so I have a lot of questions.

Will Braswell
2003 40’ Patriot Thunder
CAT C-12/Allison 4000

[Eric Maclean Co-Admin]

Will
The Jake brake system has several criteria that must be met before the engine ecu will engage it.
There is a minimum speed threshold at which is drops out ( usually 20 to 25 mph) to avoid stalling the engine
Among other considerations such as cruise control operation, throttle position gear selection etc.

On your coach I believe the Jake settings are selected via the steering wheel controls ( VIP smart wheel ).
The smart wheel has switches that use a multiplex system to talk to a VIP controller ( ecu) which then relays the command to what ever device is being requested in this way the steering wheel switches only require 4 wires to operate the cruise,Jake brake and windshield wipers etc.

First be certain that you are operating the system properly before going down that rabbit hole

Now that we got that out of the way there are a couple of posible failure point in the system .
1) the clock spring in the steering column may be bad ( the clock spring is a thin flexible mylar strip with printed circuit traces with allow the steering wheel to turn while maintaining a solid connection )
2) circuit failure bad wire or connection ( large bulkhead connectors in electrical bay)
3) power lose to the VIP controller ( circuit breaker # 30 )

First check to see if the other functions of the smart wheel are working likes the wipers and the cruise control.
Then check to see if circuit breaker # 30 has power passing through it ( third from bottom on right hand buss bar in electrical bay
From there it would be a case of trouble shooting the problem using the manual for the VIP smart wheel in the Coach assist section of the forum .

To get to coach assist go to the top of this page and click on the blue link the go to the technical tab a click for the drop down menu then click on coach assist .
There is a wealth of accumulated information in this section,go down the index and click on one of the topics to access .

There may be others here which have experienced the same issues with any luck they will chime in with their findings

Good luck and keep us updated
Eric

[Bill Lampkin]

Jake brake on my ''05 patriot thunder is via a three position switch on the dash. 

[Eric Maclean Co-Admin]

Will
It appears Bill is correct in that the Jake brake is not part of the smart wheel system on these coaches.

This should simply the diagnosis some what .
The best ( most relevant ) wiring diagram I can find for the engine brake system is in the 2004 patriot wiring diagram under page 30.
You should be able to troubleshoot the system from that

Again good luck and keep us updated
Eric

[Steve Huber]

Will,
The 02-03 Patriot Thunders have a slightly different engine brake circuit. The 2002-2003 wiring diagrams in Coach Assist show the circuit. Page 46 shows the switch wiring. Page 35 shows the eng (endurance) brake relay (K7) and page 36 shows the K7 wiring.
Steve

[Fred Cook]

My jake brake control for my 2002 PT is on the side panel next to the leveler and transmission switches. You may have a bad toggle switch. I would think a CAT dealership should be able to figure it out.

[Will Braswell]

Thank you to everyone for their input it was helpful and informative. While I haven’t solved the problem yet, I did find a remedy…hopefully. After contacting Beaver Coach sales in Oregon I found out that the control board on these leveling unit have been a real problem since their inception. BCS manufactures a new control board that provides a workaround for a malfunction control board and removes the “computerized” automatic leveling system returning it to a manual system. This should provide the remedy for this problem. Once I have it installed I will I’ll add an update as to its effectiveness.
Thanks again for the help

Will Braswell
2003 Patriot Thunder
40’ with tag axel
C-13/Allison 4000

[Steve Huber]

Will,
I must be missing something. i do not understand how the leveling system  control board has anything to do with the jake brake problem you requested assistance on. Please clarify.
Thx! Steve

[Will Braswell]

Sorry for the confusion. I’ve been dealing with multiple issues on this coach and non functioning levelers was one of them.
Evidently someone while trying to diagnose the leveler issue, had unplugged some connectors in the console and one of them was the Jake brake. The problem was when he plugged it back in they bent one of the pins causing the Jake brake to malfunction. Finding this took my tech several hours but it’s now functioning correctly. Thank you everyone for the input, it was well received.

Will Braswell
2003 40’ Patriot Thunder tag axel.