07-08-2022, 09:53 AM
07-08-2022, 10:53 AM
I just checked and my database is incorrect, it has the HT 741.
07-08-2022, 12:42 PM
https://elibrarywcl.files.wordpress.com/...4-Pc8WHWWn
The error codes for the HT741 are above, the instructions for code retrieval seem to be similar to the previously mentioned instructions.
The error codes for the HT741 are above, the instructions for code retrieval seem to be similar to the previously mentioned instructions.
07-08-2022, 07:31 PM
When you find a fix please post (got me wondering)
07-09-2022, 07:27 PM
Thank you for the the information, yes, I have the HT741. I’am still chasing down the issue, and when I get it fixed I will report back with the findings
07-09-2022, 08:00 PM
I just realized my Allison button pad does not have the UP and DOWN arrow buttons. Only R, N, D, 3, 2, 1. Is there another way to enter the diagnostic mode?
07-14-2022, 09:37 PM
Hi. Just saw this and looked around a little. Per figure 1-5 on page 1-4 of the following manual, it looks like the strip shift pads do not have a diagnostic display capability. Probably a diagnostic tool or PC connection is needed to view trouble codes. Here is the manual I found:
https://www.google.com/url?sa=t&source=w...y8NfBh7rwh
Please post any info for others' use.
https://www.google.com/url?sa=t&source=w...y8NfBh7rwh
Please post any info for others' use.
07-14-2022, 10:46 PM
I agree with Michael. The transmission issue is a probable cause of your no-start situation. Danny also has a point about engine shutdown while in gear.
You may need to clear out some temporary status on the transmission by completely removing power from it for at least 10 minutes.
You may need to inspect wiring harness/speed sensor damage as well. If the transmission cannot verify certain speeds it may, like my eaton fuller, decide to do nothing and not allow the engine to start.
10 minutes is the time that works on my Eaton Fuller Ultrashift transmission (automated manual transmission). It does not want to be shut down except in neutral as well. Like other diesels, my Volvo will demand a shut down if the coolant sensor (in the overflow bottle) goes low, even for a second, while in a sharp turn. As a result, I've experienced a few of these situations. I pull a relay and a fuse for 10 minutes and all is good. The transmission does a restart from cold and allows the engine to start. By the way, if a problem still exists it may still inhibit performance or starting.
In a completely different direction, verify that you actually have 12 volts power to your engine ECM. Its possible that broken wire at the connector may cause this situation. Watch the following video (at about 7 and a half minutes) where a Newell was disabled and the fix was a re-pin of the engine ECM power.
https://m.youtube.com/watch?v=NX2bDuNz5aA
Hope I didn't ramble too much.....Bob
You may need to clear out some temporary status on the transmission by completely removing power from it for at least 10 minutes.
You may need to inspect wiring harness/speed sensor damage as well. If the transmission cannot verify certain speeds it may, like my eaton fuller, decide to do nothing and not allow the engine to start.
10 minutes is the time that works on my Eaton Fuller Ultrashift transmission (automated manual transmission). It does not want to be shut down except in neutral as well. Like other diesels, my Volvo will demand a shut down if the coolant sensor (in the overflow bottle) goes low, even for a second, while in a sharp turn. As a result, I've experienced a few of these situations. I pull a relay and a fuse for 10 minutes and all is good. The transmission does a restart from cold and allows the engine to start. By the way, if a problem still exists it may still inhibit performance or starting.
In a completely different direction, verify that you actually have 12 volts power to your engine ECM. Its possible that broken wire at the connector may cause this situation. Watch the following video (at about 7 and a half minutes) where a Newell was disabled and the fix was a re-pin of the engine ECM power.
https://m.youtube.com/watch?v=NX2bDuNz5aA
Hope I didn't ramble too much.....Bob
07-14-2022, 10:49 PM
Could you post a shot of your keypad. I finally found an Allison keypad that looks like what I am envisioning you are describing. See Page 9 of http://manuals.chudov.com/M939-Series-Tr...Manual.pdf
If this is the keypad you have, it does not appear to support direct reading of error codes through the keypad.
If this is the keypad you have, it does not appear to support direct reading of error codes through the keypad.
07-18-2022, 03:42 PM
I’m still trying to figure out the problem. I have a picture of the rear electrical panel at the very back of the bus, can anyone help identify the circled device? Relay maybe? The circuit breaker that I have the green square drawn around appears to be bad. Also, if anyone knows what function that device serves that would be helpful too.