If you own a diesel motorhome there is a pretty good chance you have a Cummins engine powering it, especially if it was built after 2010 when some other brands like Caterpillar dropped out of the RV market. If so, and you are interested in delving deeper into the inner working of your engine, read on as the following tool may be of interest.

Cummins FaultCode Advisor is a free Android App for your smartphone. Combined with about $26 (or less) of additional hardware (discussed in detail below), it provides a quick and easy way to get a “snapshot” of any recorded fault codes stored in your engines computer, and will try and help you determine their meaning. It also captures engine model, version & serial number, plus about 50 additional parameters about the engine and related systems that go well beyond the info your dash gauges or information center can provide.

With this tool you will be able to see things like the engine computer Software ID versions, total engine hours, total fuel consumed, fuel consumed at idle, total distance traveled and most operational parameters like oil pressure and temperature, but also including more obscure values like fuel and coolant pressure. At the end of this post is the first full report I pulled from my own engine. Note that the engine was NOT running when I captured the info so for now I am assuming that explains most of the “Not Available” messages.

One important aspect to note about this tool is that it only takes a “snapshot” of the current state of your engine and systems, it does not continuously monitor those parameters like some passenger car applications. However you can take as many snapshots as you like to get information under a variety of conditions.

App & Hardware Requirements
To use the free Cummins Fault Advisor app the following items are required:

• An Android or IOS Smartphone with Bluetooth.
• An “ELM327” ODB2 Bluetooth enabled diagnostics tool.
• Most Motorhome diesels will also require a J1939 to OBD2 adapter cable.

An OBD2 (or OBD-II) tool is a device that connects to the OBD (On Board Diagnostics) port of most any modern automobile or gas powered truck or motorhome (but not diesel truck or motorhomes) built since the early 1980’s. The OBD connection can be found under the dash and looks similar to the photo left. The standard automotive OBD2 connector is trapezoidal shaped and has 16 pins. It is also know as a J1962 connector. There are many inexpensive OBD2 devices available that plug into that port and can extract data from the vehicle systems and communicate it to a Smartphone or PC. With an appropriate application that data can be presented in various ways.

However, most truck/motorhome diesel engines, do not use OBD2, they use a similar system with a round 9 pin “Deutsch” connector and support a variant protocol known as J1939. See the photo right. I don’t know all the technical specifics, but the Cummins app manages to utilize one of the inexpensive automotive type OBD2 devices connected to a J1939 port via an adapter cable to gather information from a J1939 system and display it on your smartphone.

Note that for compatibility with the Fault Advisor App, Cummins specifies that the OBD2 device must have an ELM327 chipset – the note below was copied from their description of the App:

IMPORTANT NOTE: You will need an ELM327 OBD2 Bluetooth datalink adapter to connect to the vehicle, generator, or other equipment. An adapter cable may also be required between the ELM327 and the J1939 port on your equipment. In North America, most vehicles use the 9-pin Deutsch connector for the OBD2 diagnostics port. This hardware can be found online by searching Google, Amazon, eBay, or elsewhere. Just look for “ELM327 OBD2 Bluetooth Adapter” and “J1939 9 pin Deutsch to OBD2 cable.”

Hardware Specifics:
This is the specific OBD2 device and cable that I purchased. I am not endorsing either other than to say that the combination of the two worked just fine with the Cummins Fault Advisor App. There may be other products that work just as well:

• Fineed Super Mini ELM327 V1.5 Bluetooth OBD OBD2 OBDII Scan Tool car auto Scanner Adapter Check Engine Diagnostic Tool for Android Torque/PC from Amazon. I paid $11.99 with free Prime shipping. There were less expensive ($6.99) options available for the same or similar device also with free shipping but I didn’t want to wait the three weeks for it to be delivered from China.
• Mo-Co-So 1m/39″ 9 Pin Male Deutsch J1939 to 16 Pin J1962 OBD-II Female for GPS Trackers and Scan Tools from Amazon with free prime shipping. A robust appearing cable assembly. Be sure to purchase the correct version of this cable, there are other similar appearing assemblies that have a male OBD2 connector instead of the needed female.

 

How to hook it up
The hardest part may be finding your J1939 connector. On my Spartan chassis there are two, one under the dash and another outside in the rear service center bay (passenger side last bay door where the batteries, fuel filters, air dryer, etc. are located). You may need to contact your chassis and/or coach builder to determine the connector location on your rig. I did my test with the easy to access outside connection at the rear of the coach.

Simply plug the ELM327 OBD2 device onto the end of the adapter cable. Plug the adapter cable into the J1939 connector. You will probably need to at least turn on the ignition (without starting the engine) to generate some data, that should be all you need to look for fault codes. If you want to see all information parameters under operating conditions then of course start the engine. Next bring up the Cummins Fault Advisor App and pair it with the bluetooth OBD2 device. Within a minute or two your snapshot should be captured.

So far I have found no stored error codes (yay!) and the rest of the info appears to be useful and intriguing. For example, using the total fuel consumed, total fuel consumed while idling and total distance driven I was able to calculate my lifetime fuel economy (it was 8.4mpg not counting idling time and 8.0 including all fuel burned). Also now my curiosity has been piqued in regard to the various parameters and software levels. That could be dangerous!

Just as a note, I also found this product which is a direct J1939 to Bluetooth device, no adapter cable required. However it is $225 and there is no guarantee at this point that it would work with the Cummins Fault Advisor App.

The full report from my 2013 Entegra Aspire as recorded by the Cummins Fault Advisor App and sent via email to my PC. Ignition ON, Engine not running:

The Fault Advisor is connected to Equipment, 2013 Entegra Aspire and has retrieved the following information on 19 March 2016 at 11:51 am.

INFORMATION :
Make : CMMNS
Model : 6L u10D0890000000
Serial : xxxxxxxx (edited)
Location : 26.7114403, -81.5289136 (No GPS. Location is approximate.)

100 % – Engine Coolant Level
Not Available – Engine Coolant Pressure
69.8 F – Engine Coolant Temperature
-0 psi – Engine Crankcase Pressure
865.2 ft*lb – Engine Default Torque Limit
Not Available – Engine Extended Crankcase Blow by Pressure
2400 rpm – Engine Extended Range Requested Speed Control Range Upper Limit Engine configuration
Not Available – Engine Fuel Delivery Pressure
Not Available – Engine Fuel Temperature 1
Not Available – Engine Gain Kp Of The Endspeed Governor Engine Configuration
Not Available – Engine Intercooler Temperature
Not Available – Engine Intercooler Thermostat Opening
2600 rpm – Engine Maximum Momentary Override Speed Point 7 Engine Configuration
6 s – Engine Maximum Momentary Override Time Limit Engine Configuration
16.6 lb*ft2 – Engine Moment of Inertia
Not Available – Engine Oil Level
0 psi – Engine Oil Pressure
Not Available – Engine Oil Temperature 1
46 % – Engine Percent Torque At Idle Point 1 Engine Configuration
72 % – Engine Percent Torque At Point 2 Engine Configuration
66 % – Engine Percent Torque At Point 3 Engine Configuration
82 % – Engine Percent Torque At Point 4 Engine Configuration
80 % – Engine Percent Torque At Point 5 Engine Configuration
1568.1 ft*lb – Engine Reference Torque Engine Configuration
700 rpm – Engine Requested Speed Control Range Lower Limit Engine Configuration
2400 rpm – Engine Requested Speed Control Range Upper Limit Engine Configuration
0 % – Engine Requested Torque Control Range Lower Limit Engine Configuration
82 % – Engine Requested Torque Control Range Upper Limit Engine Configuration
2400 rpm – Engine Speed At High Idle Point 6 Engine Configuration
725 rpm – Engine Speed At Idle Point 1 Engine Configuration
2230 rpm – Engine Speed At Point 2 Engine Configuration
1075 rpm – Engine Speed At Point 3 Engine Configuration
1400 rpm – Engine Speed At Point 4 Engine Configuration
2100 rpm – Engine Speed At Point 5 Engine Configuration
2693.1 gal – Engine Total Fuel Used
552.3 hr – Engine Total Hours of Operation
114.5 gal – Engine Total Idle Fuel Used
119.8 hr – Engine Total Idle Hours
45713000 r – Engine Total Revolutions
2687 gal – Engine Trip Fuel
Not Available – Engine Turbocharger Oil Temperature
37745529.2 yd – High Resolution Total Vehicle Distance
37746482.8 yd – High Resolution Trip Distance
6 step – Number of Software Identification Fields
04993120, 00187045, 062612114943, 05030506, I0, BBP – Software Identification
Not Available – Support Variable Rate TSC1 Message
17.7 gal – Total Engine PTO Governor Fuel Used
21446.3 mile – Total Vehicle Distance
4.9 gal/h – Trip Average Fuel Rate
21446.9 mile – Trip Distance

The Fault Advisor is connected to Equipment, Retarder – Engine and has retrieved the following information on 19 March 2016 at 11:51 am.

INFORMATION :
Make : NA
Model : NA
Serial : NA
Location : 26.7114403, -81.5289136 (No GPS. Location is approximate.)

The Fault Advisor is connected to Equipment, Instrument Cluster #1 and has retrieved the following information on 19 March 2016 at 11:51 am.

INFORMATION :
Make : NA
Model : NA
Serial : NA
Location : 26.7114403, -81.5289136 (No GPS. Location is approximate.)

The Fault Advisor is connected to Equipment, Cab Controller – Primary and has retrieved the following information on 19 March 2016 at 11:51 am.

INFORMATION :
Make : NA
Model : NA
Serial : NA
Location : 26.7114403, -81.5289136 (No GPS. Location is approximate.)

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Visit Cummins.com or download Cummins Fault Code Advisor for your Android Device from the Play Store.