Community Forums

87Blackman · 07-30-2021, 06:36 PM

Had my Coach for almost 15 years and 60,000 miles relatively trouble free however the end of my last trip the gremlins surfaced While traveling up a steep interstate grade I lost my Speedometer, my Check Engine and ABS Dash Light came on, and my transmission started shifting hard in the first 3 gears. Pulled over when I could; Coolant Temp OK Oil Pressure OK Belts OK. Continued home and noticed wasn't reaching full boost of 31 PSI nor torque of 1060 lbs on the Silverleaf. Reviewed Engine Diagnostics on my Silverleaf and noticed several codes including all injectors.
Took it to my Local Cat Dealer in San Diego who does all the service and they went through all the codes and cleared them; re-flashed the ECU but can not find the Transmission or Check Engine Light Fault. Engine runs fine however the same problems exist. They traced what they could for a couple of days with no luck and Cat said without a complete wiring diagram they can't check the individual systems. I don't know if a new ECU would solve the problem. Has anybody experienced this?

wolfe10 · 07-30-2021, 06:51 PM

What all those things have in common is a failure of the 12 VDC system from your chassis batteries.

A good place to start is the IGNITION SOLENOID. Voltage on one of the large lugs should be the same as chassis battery voltage all the time AND over 12.5 VDC. The other large lug should read that same voltage when the ignition is on.

Let us know what you find, troubleshooting it is pretty simple.

funjnt · 07-31-2021, 05:44 AM

That sounds like a good place to start. I would also take a look at the speed sensor.

TR4 · 07-31-2021, 06:55 AM

I would also check all your ground connections. The transmission problem sounds like it lost power and reset (re-learning).

Bill

87Blackman · 07-31-2021, 02:22 PM

Quote:

Originally Posted by wolfe10

What all those things have in common is a failure of the 12 VDC system from your chassis batteries.

A good place to start is the IGNITION SOLENOID. Voltage on one of the large lugs should be the same as chassis battery voltage all the time AND over 12.5 VDC. The other large lug should read that same voltage when the ignition is on.

Let us know what you find, troubleshooting it is pretty simple.

Thanks for the reply; I checked both sides of the solenoid 12.57 on each side rising to 13.5 with engine running.

Wheel Sensors sounds like a good culprit, I'll research prior threads to see what I'm looking for and where the connections are.

MyRVButler · 08-10-2021, 04:04 PM

Inspires are great! Theres nothing you can replace them with on the market right now. Hawthorn CAT? Did you buy your coach from us at Holland Motor Homes? I was service manager in 2006. Firstly, I figured out long ago, DynoMax basically setup their powertrains the same as Freightliner Custom Chassis does (basically after Gillig was out of the market, Dynomax went to FCCC to further develop their own platform). So, if you need service go to a FCCC dealer rather than a Prevost or Spartan. Transmission codes can be displayed via the gear selector pad on the dash. CAT might have "forgotten" how to do it. Press the up/down arrows simultaneously twice and display will enter diagnostics mode and flash codes. Your Trans manual that came in the CCI owners box will have the code chart in it. This will point you in the right direction. Dynomax Chassis used PDMs (power distribution modules) that came on with the key, your wiring issue is probably behind the fuse modules in the front run bay. I bet a wire is coming out of the backside of the fuse holder, it happens, I've seen same issues on Magna and Affinity.

Jerry · 08-10-2021, 05:30 PM

I had the same exact series of failures you had a couple days ago. I would appreciate a follow-up when you find the cause. I spent a day in the shop they could not find the cause.
Thanks in advance!
Jerry

87Blackman · 08-15-2021, 06:45 PM

Well first of all Thanks for all your responses. Yes I took it to Hawthorne Cat originally and they looked at it for 2 days but couldn't find a problem on the Cat side and they didn't have a complete wiring diagram so they didn't know where to start. To their credit I wasn't charged for their labor. Since the tranny shifting was my major concern I took the coach to Velocity Truck Center which is an Allison Service Center and also a Freightliner Dealer. I must say they are very proud of their Service Department as I listed the 3 current problems I had so they informed me that was 3 different Diagnostics and they could charge me the 2 hour minimum for each Diagnostic at their $196/Hour Shop Rate. I then asked the Advisor when did Rape become legal in Kalifornia as I would have thought with the modern plug and play Diagnostic Tools they have today they could get an idea on all 3 in 2-3 hours. The advisor chuckled a bit and said they would give me a call. Two days later they called and said the Tranny and ABS Systems were fine and it appeared it was a short in the Main Wiring Harness between the front of the coach and the engine and they had put 4 hours in so far and needed another 4 hours to find and repair the short. I gave them the OK and picked up the coach 2 days later; turns out a portion of the harness next to the exhaust system had melted from the heat so they had to remove the panels from the storage compartment, separate and repair the wiring, install heat shield cladding and then secure the wiring and reinstall the panels. Everything is fine now no codes and I'm getting smooth shifting and full turbo boost of 31.5 pounds on grades when I need it. $1,786 later I can't complain too much as other than tires and a cooling fan controller replacement right after I bought the coach have been the only major issues we've had with the coach. And yes My RV Butler the Coach was purchased from Holland RV in Kearney Mesa by the original owner who passed away 9 months later from Cancer and I believe Holland resold the coach 2007 with 6000 miles on it to a young couple who sold it to me 6 months later when the economy took the big dump and his company went from 15 employees to just him and his father so the toys were the first thing to go. We have thoroughly enjoyed the coach since our previous RV was a 27' Jamboree Class C with no slides; this has been just like taking your own luxury hotel with you wherever we go and during this time of Covid I can always say I know who slept in my bed last night.

Thanks Again, Jerry I hope this helps........

Jerry · 08-22-2021, 09:15 AM

Yep, found same thing, burned wires due to a hole in the exhaust pipe. Shop repaired wiring and exhaust pipe but the speedometer still does not work. I will take to Allison and see if they can find the problem. The shorted wiring may caused the speed sensor to fail.
Jerry

mlgunn · 08-22-2021, 09:38 AM

I had the same problem on my Inspire twice. It’s the j1939 wires. They run along the side wall and will melt together very easily. They used 70C wires. Eventually you will lose Speedo and the trans will default into 5th gear. Have them replace that section of wire and rap them in heat shield. Test the ohms to make sure your still within the spec. That should cure the problem. Allison can handle it. You might have to argue a little cause they won’t believe you at least that happen to me in Spokane. Drove in 5th gear to CC to have them repair it. If your closer to Vegas WW Williams can also repair the wiring.

Mike
06 Inspire #51808