4R70W W/82,000 miles.

My TCIL started to flash tonight when I pulled off the highway and onto a frontage road after about 20 minutes of driving.

It stops flashing when the vehicle comes to a stop and doesn't start flashing again until I reach 2nd gear. I haven't had it back into 3rd gear since this started, so I don't what will happen there.

There are no codes stored and the flashing isn't erratic at all. It simply flashes once every second and goes way when I come to a stop. I haven't had it back on the highway yet. I just drove around the parking lot here for a while and found that it starts to flash again when I get into 2nd gear.

I'm not too concerned about this right now. I'm just wondering if anyone else has had a TCIL flash like this. Just flashing once every second when reaching 2nd gear and then going away when the truck comes to a stop.

Also: It is pretty cold here. Just 4 degrees when this happened. I also had the truck washed this morning and the windchill was -20 so I suppose it is possible that water made its way into the wiring harness connections and froze.

Other than the TCIL flashing, it's not acting funny at all but, something must be wrong.....

I checked and found that there is a TSB related to the 2-3 accumulator piston causing such a problem.


Any ideas from anyone???

 

When the OD light flashes a code is stored in memory. You need a Ford specific OBDII scan tool to read the code.

It could be many things. Without the code all anyone can do is geuss.

 

Thanks, Mark. I was hoping you'd chime in here.

When I drove home this morning, I found that the light would only flash as I approached the 2-3 up-shift and sometimes on the 3-2 down-shift. After going in to 3rd gear or back down to 1st, the light would go out again. I went through the shift pattern around 10-15 times on the drive home and this happened in every 2-3 shift.

Ford has a TSB for 4R70Ws built during the time my truck was assembled regarding a leaking 2-3 Accumulator Piston. For $7.00, I thought I'd install the revised Piston & Seal assembly tomorrow and go from there.

 

Hi AJ

As Mark K. said...scan tool has to be Ford specific.

i just recently found out what that meant with my 99 a/t. 4R70W First shop could only read the OBDII DTC's...not a/t codes...but second shop had scan tool for Ford a/ts. EEC V (flashing OD light)

On my a/t, once the od started flashing..it didnt stop. Tranny was shifting differently...but i had to really pay attention..no radio/distractions etc...just ever so slightly different. Have non-Ford ext.warr...so took it in.

Code set was PO792 2/3 shift error. A solenoid was replaced.

First time repaired under Ford warr...same code...but alot more parts were replaced. However tranny shifted REALLY BAD. Dont know if more than one solenoid...but its listed on first repair.

You say your tranny shifting ok...but is it really? I dont have real answers..others mark k. FT would...but if a code was set..that would take alot of guess work out. Of course need correct scanner.

Anyhow good luck....OT

btw...im curious... about the 2/3 accumulator piston. My parts lists shows...overhaul valve body + sol asy (solinoid assembly??) 2nd repair replaced solinoid. accumulaor/valve body same thing?

 

Old Timer,

The transmission is shifting normal, for the most part. The only exception is that it seems to take extra time to go from 2nd to 3rd gear. I think what's happening inside my valve body is that the 2-3 accumulator piston seal is leaking and having problems building pressure as the transmission approaches the 2-3 shift. I'm not experiencing any hard shifts or other problems.

The accumulators, solenoids and valve body are all seperate parts. Basicaly, the solenoids and accumulators control when the trasnmission shifts and everything is mounted inside of the valve body.

The solenoinds are electrical and the accumulators are mechanical.

 

I could really use a few more brains on this one. I can usually figure these things out but this one has me stumped and it's really cold here.

On Tuesday, I removed the valve body and replaced the 2-3 Accumulator Piston. Reset the computer, went for a drive and right away had the same situation: The O/D light only blinks as I approach the 2-3 up-shift and 3-2 down-shift. It does not blink at any other time:

• Code P0713: "Transmission Fluid Temperature Sensor Circuit Input High."
• There are no drivability issues.
• The transmission shifts normal. It is not in "Limp Mode."
• Only happens during 2-3/3-2 shift.
• All gears function, including TCC lock-up.

I had the code read at a transmission shop. They checked and found that a transmission hose was leaking under pressure, at the radiator and I was down 2 qts (Basically just registering on the dip stick). They added 2 qts, tightened the hose clamp and cleared the code. They theorized that with the low fluid, the sensor was not in fluid during the shift. That, or perhaps that there was ice in the wiring harness or the sensor had failed. They didn't charge me for anything and just said to come back if it happens again. It started to flash as soon as I pulled out if their lot and the transmission shifted from 2nd to 3rd.

Today, I heated the garage up to 70 degrees for an hour to melt any ice, disconnected the wiring harness connectors and sprayed them with electrical contact cleaner. I cleaned the MAF and IAT sensors as well as the throttle body and checked the TPS voltage. After all this, I reset the computer and went for a drive again. This time the light flashed during the first 2-3 up-shift but not again. I drove around and went through all of the gear changes, including TCC lock-up about 10 times and the TCIL did not flash again.

Then tonight as I drove to work, it happened again. I drove for about 5 miles, going up and down through the gears and everything was normal. Then when I entered the freeway on ramp, the light flashed during the 2-3 up-shift and then again during the 3-2 downshift.

The code states that the input is "high." I interpret this as the sensor shorting out. What confuses me though is that the sensor only shorts during the 2-3/3-2 shifts and not at any other time. I've been imagining that it is possible that another sensor (maybe the shift solenoid) is interfering with the signal, but only during this shift.

Another thought is that because this particular sensor is a thermistor, any change would be read instantaneously and sent to the PCM, causing the TCIL. It is extremely cold here. It was -4 degrees when I came in to work tonight. I checked and did notice that the transmission fluid is at a normal temp when entering the radiator but very low when exiting the auxiliary cooler. I've been wondering if maybe the fluid is being pumped through the system and returning to the transmission pan, where the temp sensor is, at a cooler temperature than it expects to read. I have to think that others would have had this problem also though, as I'm not the only one in Minnesota with an auxiliary cooler......

I dunno

I need some additional ideas before I change the temp sensor.

Please help

 

The temp sensor won't set a code for temperature until it is at about -70F. That's not your problem. We go to cold areas every winter to develop cold weather operation. -4F would be considered a heat wave where we go!

Not having any fluid on the sensor won't cause a problem. The sensor can't tell if it is in oil or not, it can only read temperature. It doesn't care if it is air or oil temperature.

I think you have a wiring problem, most likely in the pan. The connection from the bulkhead to the thermistor is the most likely location for the problem, but it could be anywhere between the PCM and the thermistor.

Did you remove the wiring harness where it plugs into the transmission? That connector can collect water and cause funny electrical problems. Look into the transmission end of the connector, not just the wiring harness end.

I forget what year they changed from internal wires to a molded connector with the wires inside. Either way I'd drop the pan and CAREFULLY check for damage on this internal wiring. If it checks out then you need to go through the harness to the transmission.

 

Thanks, Mark

Could you please tell me what the "bulkhead" is??? I'm not exactly sure what you're referring to here.

The connections I disconnected and cleaned were on the driver's side of the transmission. One was the TR sensor and another was just above and to the right. I didn't really see any other wiring coming out of the transmission, except for the speed sensor on the extension housing. Is the wiring harness on the driver's side of the transmission??? With the weather here, it's difficult to really inspect, service and test. I basically have to heat the garage and then do what I have in mind and go for test drive. Then I come back and debate whether I should go through it all over again.

When I had the pan and valve body removed, I didn't really pay too much attention to the wiring inside, so I'm not sure if something happened to a wire in there or not. I just unplugged the electrical connections so I could remove the VB.

On my way home this morning, it was the same situation again. I drove about 10 miles without incident and then the light began to flash again as I accellerated away from a stop light. I think I'll have to wait until the temps warm up a bit next week, to continue with this.

Thanks again, Mark. I really appreciate the help.

 

The bulkhead connection is the one on the driver's side that isn't the TR sensor. Water can collect in the transmission or wiring harness side of the connector and cause a problem. It can also cause corrosion in the connector that can cause this type of problem.

It can be hard to see into the transmission side of the connector. A mirrror makes it easier.

 

It has been resolved

I hadn't realized it before but, the "bulkhead wiring assembly" is routed through the valve body at the rear, passenger side of the transmission. This is what the TCC solenoid, shift solenoid and TFT are connected to. I was looking for everything coming out on the driver's side of the transmission.

The bulkhead wiring goes through the valve body and is mounted on the outside of the transmission case. The problem is that the connection is mounted vertically/upright, so when water gets in there it has no place to go. All of the other connections are horizontal.

I unplugged the connector and sure enough, water had collected inside the transmission side of the harness as well as on the individual terminals. I sprayed electrical contact cleaner on both connectors and dried them with a hair dryer before reconnecting with dialectric grease.

I drove the same route to work tonight, under the same conditions and had no indications of a problem.

Basically, it looks like the water from the underbody wash sprayed up and the curve of the bottom side of the bed directed the water into the connector, where it became trapped and froze.

Thanks again for your insight, Mark.