Eaton 10 Speed Autoshift Drops to Neutral

Eaton 10 Speed Autoshift Drops to Neutral

Service Light Flashes - Won't Shift!!!

Flying Z
03 July 2009
12:43 PM
We were driving along just fine at 65 mph for 100 miles or better and got off the Interstate exit for a break, used the two stage engine exhaust brake down the ramp, came to the bottom and stopped liked normal, at which time the transmission shifted into Neutral by itself with the Service light on the column flashing, truck would not shift into a gear, moved the shift lever to R then back to D and still stuck in neutral, dropped it into LOW and got 6th gear, limped out through busy intersection to the rest area, the Service light continued, it was a really hot day, like 95, after half hour or so at the rest area the service light went out, the truck would start in N and then would shift into 2nd gear as usual no problem, being wary of getting on the road, I managed to get a Road Tech to respond, we cleaned the battery connections & terminals, topped off the transmission oil (he had NO better suggestions, but was happy to take my credit card), at that time no other problems apparent, NO service light flashing, so we went down the road, another 100 miles, another exit ramp, SAME STORY, stuck in N at the bottom of the exit, this time I waited for 30 minutes (next to the middle of nowhere) until we could get it into gear, the rest of the trip the service light would flash anytime I had to use the exhaust brake, but the transmission still appeared to shift normally, I never did have to come to a full stop until our final driveway and did not use the engine brake at that last turn, so we managed to limp in, never getting stuck in neutral again.

Now finally at our destination I have had time to look through the forum and manuals for info, tried to get the Fault Codes out, but using the key switch method doesn't work, the service light on the column does NOT come on and flash the codes, I've tried and tried, but can't get the sequence to work for active codes or for stored codes...

I have tried inspecting the wiring and do not find anything out of place, nicked, burnt etc.

Of course NOW the service light is NOT on at all, but somehow I doubt the problem healed itself.

Just trying to logic out the problem, I wonder if it is one of the shaft speed sensors gone bad? Without the fault codes I'm just guessing...

Any input would be helpful, of course we are in the mountains and NOT near any truck repair facility.

Oh yeah: This is a 2000 Volvo 610 with a Eaton 10 Speed Autoshift (Gen I?).

Thanks in advance for your input...

Motor31
03 July 2009
10:55 PM
No real idea about it other than to say turn off the Jake brakes.  There seems to be some kind of disconnect in the ECM or wiring related to it.  You might also check the electrical connectors at the transmission and make sure they are tight and clean.
bstark
04 July 2009
12:26 PM
Shaft speed sensors not jibing with Engine RPM due to slipping clutch when using 2 stage Jake?  ECM and tranny module not agreeing on calculated RPM triggering a safe mode?  Don't know.  I'd start with Mikes suggestion to unplug harness's at tranny, clean, coat with dialectic and re-attach.  You've then eliminated the first step for any tech to cut down on diagnostic time charged.

Does it do it bobtail with 2nd stage or just when towing?

Scrap
04 July 2009
03:27 PM
For some reason in the back of my mind I'm thinking the range valve is sticking.  Sounds kind of like it'll shift up the range fine but takes way too long to drop back down to low range after commanded.  Doesn't explain the engine brake vs. service light though.  Emery posted a good little check awhile ago.  Put the truck in R but sit still.  Hit the up arrow to put it in high range.  Then down arrow it back to low range.  If it doesn't do it or it does it too slow then you can focus on the range valve.
Flying Z
07 July 2009
10:31 AM
Scrapmaker hit it with the Range Valve sticking, finally got the fault codes out and showed 43 Range Solenoid Valve, will get one coming this way, also cleaning and inspecting all wiring and connectors, haven't found anything suspicious yet.

Thanks for the input