I have a 1999 E-350 Van that has a 7.3 and 4R100 in it. The OD light has been blinking, but I can not read any codes. I have tried multiple scanners (Snap On Solus, AutoEnginuity software on laptop with the Ford enhanced package, just to name a couple), and none of them are coming up with any codes for the transmission.

I have a TS 6 position tuner and monitor on the motor, and while going up thru the gears, it appears that the transmission shifts from 1st to 2nd fine, and it feels fine. The 2nd to 3rd shift tho is another story. It seems that the transmission is going into 3rd and immediately locking the converter. Depending on which power setting it is on, it is violent enough to chirp the tires (while it sounds fun, it cant be good). It shifts into and holds overdrive fine.

Any ideas?

Thanks in advance.
Steve S.
To many to list.

 

If Mark Kovolsky doesn't add his wisdom here shortly maybe PM him? I'm sure he'll have invaluable thoughts on this condition.


HTH

 

You can't read ANY codes? Not even a system pass code?

 

Mark,

I have no transmission related codes.

Steve S.
To many to list.

 

Do you have any codes? If so, which ones?

 

There is a waste gate solenoid code that is present. This is due to the removal of the solenoid on the turbo base. This does not throw a check engine light.

Steve S.
To many to list.

 

It's possible that you have a stuck 2-3 accumulator valve, but that won't make the converter lock on the 2-3 shift. The only time the OD OFF will flash is when a transmission code is stored. I don't understand why you have the flashing light but can't read codes.

 

Mark,
Thank you for answering this thread. That is the part that I am struggling with. The fact that I have not been able to pull a code for the transmission has me baffled. Transmission temperatures have been holding steady at 170-180 at all times on my gauge. I have not actually put a pressure gauge on the transmission to test that yet. With the display that came with the TS tuner, I can see and feel the converter locking up. I can feel it lock up in second, then when it shifts into third, it displays the shift, then immediately shows the converter locking up in third. This lock up is violent enough that it is chirping 22.5 semi tires. I can only imagine how bad that would be on stock tires.

I have not gone to the Ford garage yet. I do not know if they would have anything different or better to scan the van. As stated, it has been scanned and I have done live data watching with a Snap On Solus, AutoEnginuity, and a couple of other scanners.

I dont know if this makes a difference, but this transmission is from a Superduty, and it is a 4x4 version, as this van has been converted to 4x4.

The problem seems to get worse as I switch the tuner to the more powerful settings. ( I assume that the tuner commands more pressure from the transmission with the higher power settings ).

Thanks for any and all input.
Steve S.
To many to list.

 

Does it do this with the tuner removed?

 

I cant completely remove the tuner, as the injectors will not fire correctly with out it, but there is a "stock" setting. In this setting, the lock up is not as violent, but is still noticeable, and the OD light still blinks.

Steve S.
To many to list.

 

If you can't read codes and can't remove the tuner I have no way to diagnose this. Sorry I can't help.

 

Update time. I was finally able to come up with something. Last night I started the van up. The OD light was not blinking, I put the van into reverse, no blinking, I put the van into drive, no blinking, I idled forward, no blinking. As soon as I started moving (pressing accel pedal), the OD light started blinking. I did not shut the van off, I hooked up my scanner. I found a P0720 code. OSS sensor. I then shut the van off, turned the key on and did a scan of the computer, no transmission code came up.

I have not gone any farther as I ran out of time last night. The speedometer works fine, and cruise control works fine (I am not sure if either of these are using the OSS or not). My plan is to check the wiring on the transmission, then pull the sensor to see if there is any damage/junk on the sensor. I will see what happens from there.

Mark, does this sound like a good game plan at this time?

Steve S.
To many to list.

 

Ok, more update time and more questions. I replaced the OSS and the blinking OD light did not go away. The P0720 has come back. I have checked the continuity of the wires from the sensor to the PCM and that looks good.

I have been using Autoenginuity program to monitor some stuff. Monitoring the turbine shaft speed and the output shaft speed shows some info, but I do not know what the info means. The rpms of the shafts are vastly different while moving. I am not sure if this is suppose to be this way or not. Sometimes up to 1300 rpm difference. What other items should I be monitoring while I am doing this?

Any thoughts.
Steve S.
To many to list.

 

In first gear the turbine speed will be a lot higher than the output speed. In second gear the output speed gets closer. If the transmission is in third gear the speeds on the shafts should be within 5-10 RPM. In fourth gear the turbine speed will be higher than the output speed.

When you checked the wiring did you also check each wire (with both ends unplugged) for continuity to a power wire and continuity to a ground? The wire could still have continuity from one end to another, but if somewhere the insulation wore thought and it's touching something that will cause problems.

 

Mark,

I do not have continuity between power or either of these wires, or ground and either of these wires. I have 0 rpm on the OSS until I am moving about 10-12mph.

Steve S.
To many to list.