OD troubleshoot and A/D Transmission identification

S

strommj20

New Member
So I have been looking into my transmission not shifting into 4th gear, the manuals I have say it could either be a OD switch issue, OD solenoid issue, govenor or other valve/trans issues.

I have already tested the OD switch, and it works. The next item I'm trying to find is the OD solenoid valve, but I can't find it on my transmission, or at least the specific transmission I have is different than the specific workshop manual I'm looking at. (I'm cross referencing between quite a few manuals, including some russian Pajero manuals, which ususally end up being more reliable than the Delica ones). Another connection I have yet to check is the A/T speed sensor.

Anyway, I don't see the OD solenoid valve where it is depicted in the manuals, so I need to at this point confirm what transmission I'm working with so I can figure out where to look next.

The side of the transmission says AISIN 8980 10. I can also post the other serial number if needed, but I'm assuming this is the main model #. Does anyone know what mitsubishi transmission model this translates to? (example: V4AW3)

Also I'll share the picture of the side of the trans where the manual "says" the solenoid valve should be.
 

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Actually, so I finally read my TPS sensor after looking at the plentiful information on this forum (thanks for the how-to guide on this!).
I'm reading 5V on the TPS no matter what position it's in, I'm assuming this means I need a new TPS, and could that be causing the transmission not shifting properly?
 
How many wires are in the TPS? There should be a power (5v), ground, and signal wire which should change with the throttle position. The signal wire should never make it up to 5v, it should be somewhere between 4.5 and over 0 depending on how far the throttle is depressed. This is how it works on most vehicles, I'm assuming the same would be true on the L300's. If I had one in my bay I'd check it myself to confirm
 
strommj20 said:
Actually, so I finally read my TPS sensor after looking at the plentiful information on this forum (thanks for the how-to guide on this!).
I'm reading 5V on the TPS no matter what position it's in, I'm assuming this means I need a new TPS, and could that be causing the transmission not shifting properly?
Click to expand...
We have replaced TPS almost 100 times since 2009 for L400. Let me know if you need. Zexel original in stock.
 
B.Delica said:
How many wires are in the TPS? There should be a power (5v), ground, and signal wire which should change with the throttle position. The signal wire should never make it up to 5v, it should be somewhere between 4.5 and over 0 depending on how far the throttle is depressed. This is how it works on most vehicles, I'm assuming the same would be true on the L300's. If I had one in my bay I'd check it myself to confirm
Click to expand...
I've read that the middle wire (out of 3, blue/red) is the one to check. I'll double check the manual (which oddly enough only lists the TPS sensor troubleshooting in the gas engines)
 
So if you backprobe the signal wire and manually depress the throttle you should see the number change the further you press it. Your 5v reference shouldn't change, and your ground shouldn't change. If the signal wire starts to change and then stops before the throttle is fully depressed you've got a dead zone on the TPS and it needs replacement. If you've got nothing or a full 5v on the signal wire you've got an internal short or open and it needs to be replaced.
 
strommj20 said:
I'm reading 5V on the TPS no matter what position it's in... could that be causing the transmission not shifting properly?
Click to expand...
Yes. If the signal wire is constantly reading 5V then the ECU will think you're driving at full throttle all the time, so it won't shift to OD.
 
I found the correct wire, I think B.Delica is right, I was looking at a power line, with 5V constant. I'll double check the TPS adjustment steps with this wire.

BTW the how-to guide on here says blue-red wire. But the one that responds to throttle input on mine is the blue-yellow wire. Is this correct? Or does this potentially mean the sensor is wired incorrectly?
 
Update on the OD problem: Adjusting the TPS didn't seem to do anything. Still revving at 3500 at 100kph.
Any ideas on the OD solenoid value I mentioned in my original comment?
 
Diesel or gas, what year? On my 93 gas model there is no electronic control of the transmission shift points. I forget at what point they switched to electronic transmission control.
 
On my 1995 L400 in addition to things that make sense, ie switch, solenoid and wires, there is a temperature switch on the cylinder head wired to the trans control ecm. This locks out OD for cold temp operation. Possibly this is for faster warm up. I have posted about this before with photo. Ground wire to this switch and overdrive won't care about the cold.
 
So there's a chance my overdrive solenoid might be located inside the transmission assembly. I'm fairly confident I don't have the specific transmission model as stated in a lot of the manuals online.

Does anyone know what the corresponding make/model of transmission is from an "Aisin 8980 10"? I don't have some weird jeep transmission on my delica do I?

Otherwise, I read your other post you commented on, kbrown. I will try grounding the temp sensor and see if that's a quick fix.
 
today I grounded the coolant sensor as you wrote about in that other thread you mentioned. I am still seeing my OD issue (still reving @ 3500 @ 100kph).

Also for reference, I have tested my OD switch in the gear selector according to the procedure in the manual, and all the wires continuities were to spec. I do not have the "sticky button" issue that others have documented.
 
Aisin makes a lot of transmissions. I do believe that this transmission is also used in Jeep Cherokees behind their 6 cylinder engines. In my experience Jeep Cherokees die of a lot of things other than transmission failure.
I do not have the Delica Reference manual I have compiled at my current location. I will track it down in the next couple of days. I went down the rabbit hole, identified the transmission and found that the ATSG had a manual for it. I fixed mine before I bought their book (CD). So somewhere I have the info I collected.
I also find it hard to believe that Mitsubishi would have used more than one kind of transmission in the Delica. Each engine diesel or gas is mated to a specific transmission. In a 4wd vehicle there is a lot of stuff that mates to trans, ie engine and transfer case, multiple drive shafts. It would be complicated to make a change for a limited number of vehicles. Likely not cost effective.

PS Sad to hear that grounding sensor wire did not fix OD issue.
 
I have located some of the info I had collected on my Delica auto trans. It is also called an A340. I have attached a chapter I saved on the control diagnostics for the A340.

This shows that the OD solenoid is a 12V part so it can be connected directly to battery, single wire input (+) and grounds through case. Be careful to maintain correct polarity as some solenoids have diodes in them to prevent induced current when voltage is applied or removed.

If I want to know if solenoid is working I would disconnect wiring harness at solenoid then connect direct to battery (long test lead) and listen and feel for click as power is applied and removed. If it clicks my next step will be attach voltmeter and test drive. If on test drive I see power applied to solenoid when conditions are correct for OD engagement. The next step is remove solenoid from transmission and see if valve is stuck or seals are bad.

If no power is detected when conditions are correct for OD engagement you have to work through the trouble trees. I like to study the trees and pick a starting point that I think is more likely than others to be source of problem. Other technique is to locate where is circuit easiest to access. I think trans ecm is behind glove box(?) easy access, if power is present at ecm OD terminal it is being lost in the circuit to solenoid, If no power is being applied to OD apply circuit then it becomes more complicated and all the sensor inputs to ecm need to be confirmed as correct.

Good Luck, Kevin
 

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kbrown934 said:
I have located some of the info I had collected on my Delica auto trans. It is also called an A340. I have attached a chapter I saved on the control diagnostics for the A340.

This shows that the OD solenoid is a 12V part so it can be connected directly to battery, single wire input (+) and grounds through case. Be careful to maintain correct polarity as some solenoids have diodes in them to prevent induced current when voltage is applied or removed.

If I want to know if solenoid is working I would disconnect wiring harness at solenoid then connect direct to battery (long test lead) and listen and feel for click as power is applied and removed. If it clicks my next step will be attach voltmeter and test drive. If on test drive I see power applied to solenoid when conditions are correct for OD engagement. The next step is remove solenoid from transmission and see if valve is stuck or seals are bad.

If no power is detected when conditions are correct for OD engagement you have to work through the trouble trees. I like to study the trees and pick a starting point that I think is more likely than others to be source of problem. Other technique is to locate where is circuit easiest to access. I think trans ecm is behind glove box(?) easy access, if power is present at ecm OD terminal it is being lost in the circuit to solenoid, If no power is being applied to OD apply circuit then it becomes more complicated and all the sensor inputs to ecm need to be confirmed as correct.

Good Luck, Kevin
Click to expand...
Ahh, this is very useful! Thanks for this. I think I'll have to look through and figure out how to do these tests on the ECU, that sounds like a good method, since I cannot access my solenoid
 
I am not understanding not being able to access solenoid, is it not on the left side of transmission case forward of the speedo sensor?
On mine it sits vertical on left side of case.
 
kbrown934 said:
I am not understanding not being able to access solenoid, is it not on the left side of transmission case forward of the speedo sensor?
On mine it sits vertical on left side of case.
Click to expand...
Yea mines not there, my understanding is I would have to take off the oil pan and it sits inside. Hence why I wanted to confirm my transmission model. I hope it's not a non-stamdard model

By the way update:
I'm no longer certain I don't have 4th gear, I just thought the gearing is so strange it HAS to be in third, but here's my hypothesis;

Shifts into 2nd at 10/15 kph
Shifts into 3rd at 40/45 kph
Shifts into 4/OD at 60/70 kph

And by the time I'm at 100kph, I'm at 3500 rpm. But this doesn't make sense, the timing of the shifting shouldn't impact the gearing right?

I tried the "better than a toothpick" solution just to rule out my switch, and I've confirmed the switch isn't the issue. I bought a new TPS since the voltage was wierd when I adjusted it, but I'm still not convinced that's my issue. I will install a new TPS soon (any hints on how to install it?).

At the very least after more driving and testing, I don't think my kick down is working properly, and when I toggle my OD switch sometimes it downshifts regardless of the OD on/off signal. Sometimes it momentarily shifts and goes up like 200 rpm then goes back to the previous gear, idk it's very odd to me.

Does this information help, and can anyone make sense of my shifting points? Could a new TPS solve this, or could I by chance have a non-stamdard transmission with different gearing ratios? All of the above including the position of the OD solenoid makes me worried
 
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