Hello mudders,
I am working on developing a trans control harness and tune for my 1993 USDM 80 series so I can use a Haltech standalone ECU. I have been able to successfully map A34x series transmissions in Tacomas and for the most part the A442 (AW450-43LE) looks to function the same really. But one thing I ran into while doing my research is the presence of the "Timing Solenoid" which is practically not even mentioned in the FSM and rebuild manual.
It mentions this only...
That much I understand but there isn't any logic mentioned, is it on for the full duration of a shift, does every shift (throttle position) require it's use? It's so under defined in the FSM that there isn't even any troubleshooting associated with it that I could use to reverse engineer use case scenarios from.
Knowing this trans is common in heavy duty commercial applications I checked the relevant FSM from Isuzu and looked at rebuild guides and tips from Sonnax and even they barely acknowledge what this thing even does. Hoping someone here has walked this road before and knows a bit more. Otherwise I'm just going to have to take a few dozen drives logging TPS, RPM, Speed, and put the solenoids into the logger too so I can see what it does. Was just hoping to avoid that step, if it is as simple as it being engaged the full duration anytime one of the aforementioned shifts is occurring that is super easy to implement.
I am working on developing a trans control harness and tune for my 1993 USDM 80 series so I can use a Haltech standalone ECU. I have been able to successfully map A34x series transmissions in Tacomas and for the most part the A442 (AW450-43LE) looks to function the same really. But one thing I ran into while doing my research is the presence of the "Timing Solenoid" which is practically not even mentioned in the FSM and rebuild manual.
It mentions this only...
93-94 FSM said:
That much I understand but there isn't any logic mentioned, is it on for the full duration of a shift, does every shift (throttle position) require it's use? It's so under defined in the FSM that there isn't even any troubleshooting associated with it that I could use to reverse engineer use case scenarios from.
Knowing this trans is common in heavy duty commercial applications I checked the relevant FSM from Isuzu and looked at rebuild guides and tips from Sonnax and even they barely acknowledge what this thing even does. Hoping someone here has walked this road before and knows a bit more. Otherwise I'm just going to have to take a few dozen drives logging TPS, RPM, Speed, and put the solenoids into the logger too so I can see what it does. Was just hoping to avoid that step, if it is as simple as it being engaged the full duration anytime one of the aforementioned shifts is occurring that is super easy to implement.
