Aladdin Jr Question

[Steve Huber Co-Admin]

Am I correct in assuming the Aladdin Jr reads the CAT ECU data for display purposes only and that the engine does not use any of the Aladdin data for engine management. In other words it is a "read only" system.
Thx, Steve

[Eric Maclean]

Steve
I believe the answer to your question is yes  the Aladdin system is a read only system which gets its data via the engine ECMs serial stream data on the communication link either the j1708 ( grey six pin plug ) used from 1993 to 2001 or j1939 ( black nine pin plug) used from 2001 to 2015 when a new and improved j1939 protocol was introduced with a ( green nine pin  plug )
Each upgrade was designed to allow more data to be processed making for faster communication on the communications back bone allowing the manufacturers to add more sensors and control more components like exhaust after treatment systems.

The communication back bone is the twisted pair which allows each of the processes to talk to one another like the engine ECM and the transmission TCM also things like the ABS system so they can be integrated into power management .
The Aladdin system is plugged or tied into the communications back bone allowing it to read all the serial stream data being shared on the back bone things like throttle position ,coolant temperature, etc.
There is a large amount of data on this data buss and the buss can communicate bidirectionally this is how a scan tool can request component functions.
The capability is there for the Aladdin to communicate bidirectionally but I believe the Aladdin system was not designed or  programmed with this ability.
Many of the manufacturers frown on these so called piggy back communication systems and tuner devices as they are powered by and may introduce an unknown software creating possible failure point into their ECM.or engines by altering the manufacturers programing Which they can't control or combat against .

Sorry for the long winded explanation
In short no I don't believe the Aladdin has anything more than read capabilities.

Hope this helps
Eric

[Steve Huber Co-Admin]

Thx Eric.
I was 99% sure but a shop mechanic was saying he thought the Aladdin Jr was causing the the ECU to get faulty oil pressure readings. In a subsequent discussion he clarified that his concern was noise on the twisted pair that might have been messing up the ECU. We unplugged the ECU input to the Aladdin and symptoms didn't change. Aladdin and dash oil pressure readings OK. Replaced the fuel pressure regulator and fuel filters to resolve miss. No codes from the ECU so think we are good.
Steve

[Eric Maclean]

Steve
As I said earlier most OEMs don't like aftermarket devices connected to their network for exactly that reason.
And u fortunately many problems get blamed on these devices when in fact the problem lies somewhere else.

If there is a problem with noise on the twisted pair which is creating problems with communication the first things to look at are things like alternators or motors which can create such electrical noise.
Alternators can have rectifier issues which will generate a volt ripple which will create all sorts of problems with the network communication.
The twisted pair in the backbone may run the entire length of the coach and does have a grounded shield over the twisted pair to stop interference but even with the shielding if it runs too close to something like a blower motor it can pickup induced voltages and electrical noise.
To rule out the alternator you can simply disconnect it and test and the same goes for motors just shut them down and see if your problem is elevated.
In some cases the fix can be as simple if a capacitor connected to the device in questions power power.

Hope this helps
Eric