What could this TOGGLE SWITCH be for???

Highway Yacht · February 15, 2009, 11:14:10 AM

I just noticed this toggle switch a couple days ago on the Push Button panel box that goes to my Allison Automatic V731 transmission. I have no idea what it is for. HighTech Redneck thought it MIGHT could be a retarder switch but I don't know if I have a retarder. The Toggle Switch is spring loaded and seems to be a 3 way switch. You can flip it up one notch or down one notch but it will always spring back to the center position just as soon as you take your fingers off the switch. Anybody else have any idea of what this switch could be for other than a retarder or can tell me where to look for a retarder??? You can see the Toggle switch in the photo below. It is about halfway down in front of the Push Button panel box just below the RED toggle switch cover. Btw, its on a 1989 RTS bus with the 6V92 DDEC - V731 setup.

RTS/Daytona · February 15, 2009, 11:25:53 AM

It's the DDEC (engine) and ATEC (Transmission)

DIANOSTIC TEST SWITCH

Just turn on the run switch (no need to start the engine) and hold the test switch up

Then
<>count the light flashes on the CHECK ENGINE and/or STOP ENGINE for the 2 digit engine error coded 25 = NO CODES
<>count the light flashes on the TRANS light for the 2 digit tranny error codes

Pete RTS/Daytona

If you need manuals - let me know

Highway Yacht · February 15, 2009, 06:06:36 PM

Thanks Pete.. I tried the switch and it gave me the codes for the DDEC but I never could get any codes or flashing lights from the ATEC. I got 3 codes on the DDEC when I used the test switch.

#16 Coolant Sensor Hi Volt
#22 Throttle Pos Sensor Lo Volt
#41 Timing Reference Sensor

Not sure what these codes mean or even if they are current codes or stored codes from days gone by. Wouldn't the check engine light be flashing if it was a current code when the bus is running? When NOT using the test switch, the check Engine light comes on for maybe three seconds (no blinks) when I turn the power switch on but then goes out and it never comes on again while running or driving. The ATEC "do not shift" light comes on and blinks 3 quick blinks and then goes out when I turn the power switch on and then no blinks while running or driving.
Could these DDEC codes be from old problems and is there anyway to find out??

I do not have the Manuals. Is there anywhere I can get a copy or download them?

Blacksheep · February 15, 2009, 06:50:27 PM

Your yellow check engine light and a red stop engine light will come on when you first turn the key. This is the ecm doing a self diagnostic test. Your supposed to wait until these lights go out before cranking. Not sure about the atec unless your switch activated the opposite direction from the ddec will do it.
You can't erase any past or historic codes without a data reader such as a pro-link.
The code chart is available on-line if you type in google for ddec codes. Most of what yours are are probably just bad connections but check them NOW because sooner or later they WILL come out and get you and more than likely, at the worst possible place and time!
Ace

Highway Yacht · February 15, 2009, 08:02:19 PM

Quote from: Blacksheep on February 15, 2009, 06:50:27 PM
Your yellow check engine light and a red stop engine light will come on when you first turn the key. This is the ecm doing a self diagnostic test. Your supposed to wait until these lights go out before cranking. Not sure about the atec unless your switch activated the opposite direction from the ddec will do it.
You can't erase any past or historic codes without a data reader such as a pro-link.
The code chart is available on-line if you type in google for ddec codes. Most of what yours are are probably just bad connections but check them NOW because sooner or later they WILL come out and get you and more than likely, at the worst possible place and time!
Ace

Since the "Check Engine light" goes out right after the ECM does its self diagnostic test, does that mean that the 3 codes I got while doing the test are historic codes and have probably already been fixed?

Blacksheep · February 15, 2009, 08:11:29 PM

If the lights go out, your ecm is ready to rock and roll. If, after the engine starts, the CEL comes on, you will have an active code/s. If it's a bad code, meaning harmful to your engine, the STOP engine light or SEL will come on for about 5 seconds and activate an engine shut down! Time to look deeper into your problem if that happens!

Ace

Highway Yacht · February 15, 2009, 08:25:47 PM

Great...Thanks.. All my lights do go out within seconds of the engine starting and always have since I have owned the bus (3 years) so they must be very old codes from the previous bus company. At least I will be able to sleep tonight without worrying that I have current code problems.

RTS/Daytona · February 16, 2009, 06:05:04 AM

When the DDEC (Detroit Diesel Electronic Controls) and the ATEC (Allison Transmission Electronic Controls) are first powered up they will go thru STATIC SELF CHECK and

The DDEC will Flash the "CHECK ENGINE LIGHT / STOP ENGINE LIGHT and if equiped the CRUISE CONTROL ACTIVE LIGHT for 5 seconds and go off if no active errors

The ATEC will Flash the "DO NOT SHIFT LIGHT" 3 times and go off if no active errors

DDEC-II - The CHECK ENGINE LIGHT will remain on if an ACTIVE error exists (unfortunately there is NO WAY to tell active errors from historical errors when you flash the codes - so write down your inactive codes - this will help if you get a new/different code - but will not if the same inactive codes goes active again - sorry ddec-ii are dumb

DDEC-III & IV - ACTIVE CODES flash the "SEP - STOP ENGINE LIGHT in diagnostic mode" and INACTIVE codes flash the "CEL - CHECK ENGINE LIGHT"

Inactive codes can be reset with a PRO-LINK - I've heard that removing power "for a few days" will also do it - but I doubt it"

THE "SEL - STOP ENGINE LIGHT" comes on when:
.....<> error 43 COOLANT LEVEL LOW FOR 7 SECONDS or more
.....<> error 44 OIL or COOLANT HIGH TEMP 2 SECONDS or more
.....<> error 45 LOW OIL PRESSURE for 7 seconds or more

"IF" your DDEC has been programmed to SHUTDOWN (MOST ARE) -- the SEL will SHUTDOWN THE ENGINE
"IF" your DDEC has been programmed for "STOP ENGINE OVER-RIDE" - holding the STOP ENGINE OVERRIDE SWITCH will allow you to move the bus OFF THE ROAD

Pete RTS/Daytona

JLINK - send me an email - I have a source for all the RTS and V731 Manuals on CD or DVD hawk_ii_mail at yahoo.com or ...386..672..0571...

NJT 5573 · February 16, 2009, 11:05:42 AM

jlink,

All the DDEC info you will ever need is free at a link at the bottom of our page 15, soon to be page 16, called DDEC Motherload for free. The DDEC info starts about halfway down that page and goes on forever. I particularily liked the way DDEC wires are locked to the harness. That increased my faith in the system, but if I had it to do over again I would stay away from electronics.

The first code DDEC gives you is the most recent. In my experience the great majority of codes are hickups and glitches, but if it quits running, the code is going to get you running again in most circumstances if you can follow the instructions.