moorep01 Report post Posted March 25, 2019 We recently purchased a 2008 Holiday Rambler Endeavor on the Roadmaster rr8r chassis with a Cummins ISL 400 and Allison transmission. This is our 3rd motorhome but our first diesel pusher. On a trip last week we had a Warning light on the dash to come on intermittently. No other light comes on and there is no audible warning. Seems to come on when I tap the brakes on a downhill stretch. It will stay on until I hit a bump in the road. If I am at a red light when the Warning light is on the transmission seems to delay shifting out of 1st gear. If I am driving along and the warning light is on and I let off of the accelerator it feels like the transmission downshifts to a lower gear. When it is off everything seems OK. It may go a couple of hundred miles between the light coming on. I have checked all fluids that I know of and done the air brake system test. The previous owner told me the coach was serviced last October. Any ideas would be appreciated. Share this post Link to post Share on other sites
huffypuff Report post Posted March 25, 2019 Can you give us a clue what the light looks like? Share this post Link to post Share on other sites
manholt Report post Posted March 25, 2019 moorp01. Welcome to the Forum! Do you know if the Allison was ever serviced? How many miles is on the coach? Trans might be low on fluid or need a filter replacement. Share this post Link to post Share on other sites
hermanmullins Report post Posted March 25, 2019 Yes, Welcome to the Forum. Just a guess on my part, Sound to me that you are having problems with your "ABS" system. Herman Share this post Link to post Share on other sites
wolfe10 Report post Posted March 25, 2019 moorep01, Welcome to the FMCA Forum. Have you checked the transmission for diagnostic codes? Very easy from the driver's seat. Instructions in you Allison manual, or we can post that information here. Share this post Link to post Share on other sites
moorep01 Report post Posted March 25, 2019 Thanks for all the replies. It just says warning on the very left of the dash. I do not know if the Allison transmission was ever serviced. According to the keypad test the transmission fluid is not low. The coach has a little over 55,000 miles. It has about 3000 miles and 5 months since it was serviced according to the previous owner. Is there any test to check the ABS system? Thanks again. Share this post Link to post Share on other sites
moorep01 Report post Posted March 25, 2019 I just saw online how to check the transmission for diagnostic codes. I'll try that this afternoon. Thanks Share this post Link to post Share on other sites
jleamont Report post Posted March 25, 2019 Warning usually designates a fault code in the engine ECM. Usually related to an issue that will not leave you stranded. You will need to have the codes retrieved from the engine ECM soon. Often when Warning is illuminated the engine will go into a limp mode where it might cause the transmission to shift different. Share this post Link to post Share on other sites
manholt Report post Posted March 25, 2019 Also, on mine, the far left is regeneration! I don't remember if the 2008 is a left over 2006 on the assembly line, if it is...Lucky you! Share this post Link to post Share on other sites
moorep01 Report post Posted March 25, 2019 If I remember right, the build date was August of 2007. It must have sat on a lot somewhere for over a year. The first time it was purchased was May of 2009. Either because of the problems of 2008 or because the shorter coach was not desirable. Share this post Link to post Share on other sites
manholt Report post Posted March 25, 2019 Chassis date is the important one! Share this post Link to post Share on other sites
wolfe10 Report post Posted March 25, 2019 And, engine build date may be well before chassis build date. Particularly true right after the date of tightening of EPA standards. So, common for chassis builders to buy large quantities of engines that are less expensive and less complex just before tightening standards. All perfectly legal and ethical. Share this post Link to post Share on other sites
manholt Report post Posted March 25, 2019 And a blessing for us! Share this post Link to post Share on other sites
moorep01 Report post Posted March 25, 2019 I went to the Cummins site and put in my serial number then went to data plate. It has engine build date is June 25, 2007. Does that help? Share this post Link to post Share on other sites
wildebill308 Report post Posted March 26, 2019 Keep your serial number handy, you will need it whenever you talk to a Cummins parts guy. What site did you use? https://quickserve.cummins.com/info/index.html This is the same site the dealer looks at to find information on your engine based on the serialnumber. Bill Share this post Link to post Share on other sites
moorep01 Report post Posted March 26, 2019 If I did the transmission diagnostic test correctly, there were no codes for d1, d2, d3, d4, or d5. It was raining here so I didn't get a chance to look at ABS wiring or resistance checks on the sensors. Always tomorrow. Yes, WILDBILL308 that was the Cummins site I went to, then logged in with user name and password. Thanks everyone. Share this post Link to post Share on other sites
manholt Report post Posted March 26, 2019 You have the new Particulate filter that I have. In your owners manual there is a section, that tells you what to do, when it regenerate...with mine, I just keep driving and i takes about 18 minutes. There are some, that you need to find a place to stop, put it in neutral and let engine idle until light goes off...do not turn off ignition! It can cause you to buy a new one! Share this post Link to post Share on other sites
moorep01 Report post Posted March 26, 2019 Thanks Manholt, I'll look that up in my manual. Share this post Link to post Share on other sites
wolfe10 Report post Posted March 26, 2019 If your Allison check brought up d-1 - - there are no stored diagnostic codes. That is what the blank-blank means. Share this post Link to post Share on other sites
moorep01 Report post Posted March 26, 2019 Thanks wolfe10. I appreciate your help. When I did the Allison test, I pushed the up and down arrows twice. It brought up d1 -- --. Then I pushed the mode button and it went to d2 -- --. I continued pushing the mode button through to d5 -- --. So I should be good right? Share this post Link to post Share on other sites
wolfe10 Report post Posted March 26, 2019 Yes, you did it absolutely correctly. Once you get a - - (blank blank), no need to go further. Only need to use the mode button to "go further" if there IS a diagnostic code. Brett Share this post Link to post Share on other sites
moorep01 Report post Posted March 26, 2019 Thanks Brett. I have had several switches all through the coach that haven't worked. All have been issues with ground wires. Since my warning light goes out when I hit a bump in the road, do you think I may have another ground wire issue somewhere? It's funny the light on the dash only says Warning with no other indication. Thanks again. Share this post Link to post Share on other sites
jleamont Report post Posted March 26, 2019 1 minute ago, moorep01 said: Thanks Brett. I have had several switches all through the coach that haven't worked. All have been issues with ground wires. Since my warning light goes out when I hit a bump in the road, do you think I may have another ground wire issue somewhere? It's funny the light on the dash only says Warning with no other indication. Thanks again. I had the same issue 2 years ago. Just "warning" lit up, no engine light. It turned out to be a fault code in the ECM for one of the two Cam position sensors. Per Cummins "Warning" is an active fault code that needs immediate attention but you can still drive/limp it somewhere for repair. I put another 150 miles on it to get home and address it then. Share this post Link to post Share on other sites
moorep01 Report post Posted March 26, 2019 Thanks jleamont. It's odd that the light will go out when I hit a bump. I drove probably 200 miles last Saturday without seeing the light come on at all. I guess the next step is to take it somewhere and have the codes checked. Share this post Link to post Share on other sites
wolfe10 Report post Posted March 26, 2019 Could also be something as simple as an ABS sensor with incorrect/excessive clearance. Share this post Link to post Share on other sites
