Author Topic: ECM Data MISSING from Aladdin  (Read 2761 times)

Russ Mann

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ECM Data MISSING from Aladdin
« on: June 04, 2020, 08:33:25 PM »
The C9 Engine operating information is missing on the Aladdin Engine screen, only XXX is displayed where the data should be. ALL other information and screens work fine. Also the Sony display does not power up or down automatically with the ignition switch.  The ECM data is an RS485 twisted pair that goes to the Aladdin Control Module above the drivers window and it is firmly connected along with the 12VDC and ground on the same connector.
Does anyone know if the twisted pair (black and white) with black covering has another connection or plug under the dash?
What relay or other item switches the Sony display on and of with the key?

Thanks, Russ

Eric Maclean

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Re: ECM Data MISSING from Aladdin
« Reply #1 on: June 04, 2020, 11:50:50 PM »
Hi Russ
The twisted pair should lead you to VIM ( vehicle interface module) probably up under the dash or on the electrical bay.
The vim is the gateway to the engines ECM via the diagnostic connector.
Your lack of information display would lead me to think you may have either a connection problem or a failed VIM module
Hope this helps
Eric
1997 Patriot Yorktown
3126-B
2009 Chevy HHR
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Bill Lampkin

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Re: ECM Data MISSING from Aladdin
« Reply #2 on: June 05, 2020, 02:05:40 AM »
If your VIM module is kaput, used modules might be found at an RV salvage yard!
Good luck in your search.
2005 Patriot Thunder Lexington, 3 slides
40' tag axle (short wheelbase)
525 hp C13

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Scott Shearer

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Re: ECM Data MISSING from Aladdin
« Reply #3 on: June 05, 2020, 10:07:44 AM »
I know that there are differences in the 12VDC circuitry between our coach and yours (i.e. fuses vs circuit breakers), but I will share what I know about the Aladdin system in our coach. I would think that the basics for the Aladdin system would be similar.

The Aladdin Video Control Module (VCM) is the main processor for the Aladdin system. All sensors, joysticks, and bus taps receive their power from the VCM. Aside from the AV circuitry, there are two fused power sources for the VCM, one is constant 12VDC from the house batteries and one is ignition switched 12VDC from the chassis batteries.

Main power is supplied to the VCM from the rear run box, it is protected by a 7.5-amp fuse labeled Aladdin. This circuit supplies constant house battery power to the Aladdin VCM, power goes to the Aladdin reset switch then to the ‘+12 SWX’ pin on the ‘House Bus’ port of the VCM. This is the main power source for the VCM and allows you to power on the Aladdin system from the joysticks or the remote tank monitor in the service bay. The Aladdin VCM WILL NOT power on without this circuit hot. This circuit is likely not your issue.

There is a second fused circuit located in the front run box that supplies 12VDC ignition power to the ‘+12 IN’ pins on the ‘Engine Bus’ port of the VCM. This circuit allows the Aladdin system to power on/off with the ignition key. The Aladdin system can function without power to the ‘Engine Bus’ port but you would have no engine/trip information and the system will not power on/off with the ignition key, you must use a Joystick or the remote tank monitor. (This circuit is incorrectly labeled ‘15A Level’ on our coach, also in the wiring diagrams). This circuit is likely causing your problem.

Also, there is a module called J1939 Bridge that interfaces the Aladdin ‘Engine Bus port’ with the J1939 backbone from the engine ECM. The J1939 Bridge translates the engine ECM data for the Aladdin VCM. On our coach, the J1939 Bridge is located in the ceiling of the driver side first storage bay, along with several other controllers (HWH level, VIM, etc.).

A bad fuse on the Aladdin Engine Bus circuit (front run box on our coach), broken wire/faulty connection or a faulty J1939 Bridge or could produce the symptoms that you described.

According to the electrical diagram, all DC circuits connected to the VCM are protected from voltage spikes by a 1500-watt 24V surge suppressor (TVSS), I have not looked for the surge suppressor so don’t know where it might be located, what it looks like or even if it exists. Given that your ‘other’ Aladdin functions are working the surge suppressor is not likely your issue.

As I mentioned above, this is how our Aladdin system is setup, yours may be different. Hope this helps you trace down your Aladdin issue.
Scott & Susie Shearer
2006 Patriot Thunder
Lexington IV 40'
Cat C13
2015 JKU Hard Rock
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Mike Shumack

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Re: ECM Data MISSING from Aladdin
« Reply #4 on: June 05, 2020, 01:59:56 PM »
The Aladdin Bridge module appears to be used on 2006 and up models from what I can tell. I don't have that on my 2005 PT (afaik).
I think it came about when the Patriot moved from the Magnum chassis to the Roadmaster chassis (and went to multiplexing).

Do you have any wiring diagrams showing the "Bridge module"? I'm curious if it is connected to the ECM bus at the same place (under the dash) as the non-Bridge systems.

Is that Bridge module used to provide "gauge data" (I see a pin marked "fuel sender") for this dash gauges that are multiplexed together?

This diagram below is for models up to and including 2006 PT - but does not show that module.

« Last Edit: June 05, 2020, 02:16:47 PM by Mike Shumack »

Scott Shearer

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Re: ECM Data MISSING from Aladdin
« Reply #5 on: June 06, 2020, 05:55:43 AM »
Mike,

I cannot say if the J1939 Bridge was used prior to 2006 model year, it would be interesting to know for sure, but I have found little information relating to the module. I found the Bridge Module on our coach while troubleshooting an issue with the Check Engine and Engine Warning lamps. I had a Cat technician tell me that the Check Engine, Engine Warning lamps and dash gauges were controlled by the Aladdin system and that the Aladdin system was the cause of our lamp issue (he also noted the inaccuracy of the engine and trans temp gauges). I did not buy his explanation, so I started researching.

I obtained a diagram of the J1939 backbone from REV in Coburg. That diagram showed various branches and terminations including the front and rear diagnostic ports, VIM connection and the Aladdin connection. It showed the Aladdin connection to be forward of midship. That is how I found the Bridge Module; I did not know it existed prior. When I found a module that was labeled J1939 Bridge I thought, oh boy, the technician was right after all.

I spent several more hours reviewing diagrams and troubleshooting our Aladdin system, what I discovered is described above. Also, disconnecting the Aladdin VCM Engine Bus or the J1939 Bridge (one at a time) had absolutely NO effect on the Check Trans Lamp, Check Engine Lamp, Engine Warning Lamp, or dash gauges. All that did was to cause the Aladdin system to display all ‘Xs’ for the engine and trip information and the system would not power on or off with the ignition switch. Same results when pulling the fuse in the Front Run Box. As I suspected, the ‘dash engine information’ on our coach is analog and not at all controlled by the Aladdin system.

I do not believe that the multiplex system plays any part, the multiplex system is for the domestic side of the coach, we do not have the Kongsberg chassis mux like the later 2008 and up coaches do.

In terms of the pin marked ‘fuel sender’, I did not trace that circuit, I suspect that it is not used in our application.

The diagram that you included is also in the Aladdin troubleshooting manual, it is not correct for our coach, it may be for an older versions of the VCM. That manual is helpful but seems to contain several errors and leaves a lot to guess work.

I have misplaced the diagram of the J1939 backbone, if I find it, I will post it to the group.

I used the diagram below and the detailed diagrams of the Front and Rear Run Boxes to determine the circuits powering the Aladdin VCM.
Scott & Susie Shearer
2006 Patriot Thunder
Lexington IV 40'
Cat C13
2015 JKU Hard Rock