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Transmission/Electronic control problem D6

Wreckless1

New member
I am having a major problem with one of my 2007 D6 engines. The transmission will not go into gear nor can I increase the rpms. The EVC codes indicated a bad secondary solenoid. We replaced both solenoids on the transmission but still would not go into gear. The volvo mechanic then tried switching the computer from that engine with the other engine and when we could get it engage, which was only occasionally, it would be reversed, i.e. putting into forward put it into reverse and vice versa. The trans is a zf hurst, 80AE. I have had several mechanics working on this with no solution. They have tried reprogramming to no avail. I first had the problem after leaving the marina and suddenly the engine was in neutral. I played around with it at the dock before any mechanics looked at it and several times I got it to go into gear but it was reversed, that is putting it into forward caused it to go into reverse. That was before trying to switch out the computer. All the mechanic has been able to tell me is that some sensor is telling the computer there is a major problem and not to allow it to go into gear. I also am unable to increase the rpm above idle. Complicating things is that the boat is in Mexico. I am looking for some experienced input as to what to check or do. I would hate to buy a new computer without being sure that is the problem.
 
Have you tried swapping the control levers over? Could it be a control head problem maybe? I don't know the D6 electronics very well but I assume it is just a plug connection to the control levers? Might need to check if you need to tell the computer the address of the swapped control lever. I wouldn't think so but that could be possible I guess.
System is probably sensors, ECU, solenoids, & control head so if the swapped ECU and Solenoids haven't done it maybe the control head might.
Will the engine increase in rpms if you do it without engaging the gears (using the fast idle type feature etc)?
 
Have you tried swapping the control levers over? Could it be a control head problem maybe? I don't know the D6 electronics very well but I assume it is just a plug connection to the control levers? Might need to check if you need to tell the computer the address of the swapped control lever. I wouldn't think so but that could be possible I guess.
System is probably sensors, ECU, solenoids, & control head so if the swapped ECU and Solenoids haven't done it maybe the control head might.
Will the engine increase in rpms if you do it without engaging the gears (using the fast idle type feature etc)?

I am not sure if they tried switching the control head, that was my last suggestion that they focus on the on the control head because my parts supplier told me there is a switch there that frequently goes bad and the engine will not start because it does not signal that it is in neutral and I thought that could be something in the control that is malfunctioning. Language is a problem but I believe they told me they tried switching the controls and they still had the issues. The volvo mechanic seems to think that there is a sensor that is telling the computer there is an engine problem which is also why I cannot raise the rpm on that engine above idle. Sometimes when I start that engine and the alarm goes off the tachometer will read 0 and I cannot get it to show anything else but the engine is idling.
 
The confusing thing is the shift going into reverse instead of forward. The engine sound like it is in safe mode which could be from a sensor problem etc but the backwards shifting is very strange. Not sure how Volvo drive the tach on the D6 unfortunately. A lot of their older engines were driven from the alternator output but I suspect the electronics ones may use output from the crank angle sensor or even an extra sensor for this.
Have the mechanics checked that the correct solenoid is being operated for each gear direction to prove that it isn't some strange hydraulic issue in the gear box? I have never heard of that happening but it is a 5 minute test (voltage on the solenoid feed) to take the gearbox out of the equation.
 
I thought I would post the outcome and eventual solution and long story. I don't recall if I mentioned that this was all happening in Mexico with language difficulties for me to deal with too. We could not find a volvo mechanic and so my mechanic took the main computer out and took it to an electronics place in Cancun. They said it was fried and it did look blackened inside. So I bought a new one for $4400 from a volvo dealer and brought it to Mexico, it had to be programmed with a Vodia for my engine. I ended up bringing in a Volvo Penta mechanic from another Caribbean island with a Vodia computer (cost $1300). He reprogrammed the old computer and the other 2 computers, and the boat runs fine. We never used the new computer. I suspect that all of the problems were related to jump starting the boat with a dead battery which affected the computer. I suspect that I might not even have needed to replace the solenoids in the transmission. Anyway, it just needed to be reprogrammed. I have put 12 hours on the boat since repairs. I now have a new computer that I would sell to anyone for half price, just $2200, its for a D4/D6 engine if you hear of anyone needing one, send them my way. They would just need to have it programmed for their engine.
 
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