1998 3.0 4wd XLT 4r44e P0715 code and flashing OD

[azrangerman85]

I have a flashing OD light and the code says p0715 , " Turbine Input Speed Sensor Circuit "

the only speed sensor I can visually locate is the rear differenetial . I tried diagnosing it , the transmission was shifting hard but it was shifting into all gears , so if I go and shut it off the light flashing turns off , sometimes it doesnt come on at all. I put half a quart of Maxlife Valvolone atf because it has detergent and I wanted to see if the sensor was being thrown off from break in material ( 55,000 miles ) . Once I put the maxlife atf half quart in, the flashing light started to disappear , reappear then disappear then finally disappear for way longer . It flashed today after driving 2 days without it then it turns off again . Is this a filter/ fluid needing changing ? And which sensor is it since Oreillys sold me a speedo sensor i cant even visually locate?? I dont think there is a speedo style sensor on my transmission model any help is wanted. I dont want negative " rebuild" it bullshit . Only serious diagnostics

 

[RonD]

1998-2000 Rangers used the rear axle ABS sensor and GEM module for vehicle speed, i.e. speedo/odo, computer and cruise
Only for these 3 years and nothing to do with TSS sensor


TSS(turbine shaft speed) sensor is inside the rotating part of the transmission so trans removal and disassembly is required to change it, bummer

But keep a good thought, lol, could be a wiring issue

On the drivers side of transmission, in front of shifter, is the 16 pin connector for all the solenoids and sensors in the transmission
(same connector and wiring was used in Rangers 1995 thru 2011, 4R and 5R)
Seen here:

TSS + and - are pins 2 and 3
Use an OHM meter and see if it shows 64-126 ohms
If not then all is not lost YET

Drain fluid and remove the pan
TSS has a 2 wire lead that is attached to sensor but is plugged in inside the pan and connection might be the issue, you can test sensor directly at that connection

This is TSS sensors location: https://www.explorerforum.com/forums/attachments/3386-jpg.264888/

You are looking at the front of transmission with bell housing and "guts" removed
TSS is that black unit at 5:00, has wires that run down and into the valve body pan area

TSS sensor's main function is to tell computer that engine RPMs and input shaft RPMs are matched, its why its called "Input/Turbine Speed Sensor"
This tells the computer that torque converter is "locked" if its suppose to be, so engine and trans input shaft are at the same RPM

P0715 is also a ".....Circuit Malfunction" code so its not that TSS is reporting different RPMs, its saying its not reporting anything at certain times
Its intermittent, so could be a wiring issue

 

[azrangerman85]

both my dad and I dont recall a sensor on the inside of the bell housing. I have only a tiny little guitar jack sizes plug thats on the top center of the tranny ( maybe vent? or speedo?) and the rear differential has a speed sensor, I cleaned off the terminals there and repluggd it in it seemed a tad loose enough for dirt over the years . Also ... the intermitent OD flash was lastnight but this morning to afternoon it hasnt turned on at alllllll since I added seafoam trans tune before I drain the pan. Im waiting for a pan I ordered that has a drain bolt , ill remove the original pan and inspect the magnet and post pics soon . so far the od isnt flashing i cant figure this out its annoying why it went away and only comes on ocassionally for p0715

 

[azrangerman85]

1998-2000 Rangers used the rear axle ABS sensor and GEM module for vehicle speed, i.e. speedo/odo, computer and cruise
Only for these 3 years and nothing to do with TSS sensor


TSS(turbine shaft speed) sensor is inside the rotating part of the transmission so trans removal and disassembly is required to change it, bummer

But keep a good thought, lol, could be a wiring issue

On the drivers side of transmission, in front of shifter, is the 16 pin connector for all the solenoids and sensors in the transmission
(same connector and wiring was used in Rangers 1995 thru 2011, 4R and 5R)
Seen here:

View attachment 96108

TSS + and - are pins 2 and 3
Use an OHM meter and see if it shows 64-126 ohms
If not then all is not lost YET

Drain fluid and remove the pan
TSS has a 2 wire lead that is attached to sensor but is plugged in inside the pan and connection might be the issue, you can test sensor directly at that connection

This is TSS sensors location: https://www.explorerforum.com/forums/attachments/3386-jpg.264888/

You are looking at the front of transmission with bell housing and "guts" removed
TSS is that black unit at 5:00, has wires that run down and into the valve body pan area

TSS sensor's main function is to tell computer that engine RPMs and input shaft RPMs are matched, its why its called "Input/Turbine Speed Sensor"
This tells the computer that torque converter is "locked" if its suppose to be, so engine and trans input shaft are at the same RPM

P0715 is also a ".....Circuit Malfunction" code so its not that TSS is reporting different RPMs, its saying its not reporting anything at certain times
Its intermittent, so could be a wiring issue

I removed the oem transmission pan , drained the ruby red atf ( it was clean and transluscent no burnt oil) .The magnet had no shards, it was normal. I cleaned it up and put it in the new pan. I replaced the oem pan with a 60 dollar pan that has a drain bolt . I replaced the filter which did look filthy , I put a premium wix filter in with lubed orings on the in and outlet , I bolted it all up corner to corner star pattern and sealed it up.6 Quarts is exactly what came out when I emptied my oil pans into a home depot hdx painters 10 qt bucket. I uses 1 gallon and 2 quarts of Valvoline Maxlife atf to fill her up, I put the key in, shifted to neutral, then into 1st and 2nd then neutral then reverse . Allowed it to move ... checked the dipstick and its exactly at the checkered marker running hot . I ran it down the road and it drove like new, all shifting had power and smooth. the speed sensor circuit OD light came back intermittently but goes away and at this point its not effecting the smooth like new shifting. Back to square one ... it has to be a wire??? But like I said I dont recall a sensor in the bellhousing. Ford is stupid for having too many versions of these transmissions ... I need to know where that sensor is . Maybe im not seeing it or feeling it on top of the transmission housing . I also checked the wiring in the valve body it looks new and nothing is loose or frayed . Nothing looked dirty or burnt. this can be a gem module/ wire outside or the harness plug voltage itself. Any more input? Who should I have analyze it ? I dont want an average dumb mechanic

 

[RonD]

Not in/on the bell housing, you can just see it if you remove bell housing and the internal parts
It's located on the Center support, #47 in diagram, TSS is #45

Diagram: https://ww2-secure.justanswer.com/uploads/fordtech12/2010-05-20_223914_1.gif

Diagram is from this article: https://www.justanswer.com/ford/3j2vr-turbine-speed-sensor-location-1998-ford.html

 

[azrangerman85]

Not in/on the bell housing, you can just see it if you remove bell housing and the internal parts
It's located on the Center support, #47 in diagram, TSS is #45

Diagram: https://ww2-secure.justanswer.com/uploads/fordtech12/2010-05-20_223914_1.gif

Diagram is from this article: https://www.justanswer.com/ford/3j2vr-turbine-speed-sensor-location-1998-ford.html

What type of mechanic is qualified to analyze the electrical of a transmission harness and internal sensors? I dont want some dumb shop mechanic , Im talking someone who has brains . Is aamco trustworthy?

 

[RonD]

You just need an OHM meter

 

[azrangerman85]

You just need an OHM meter

Got it.... but if I use an ohm meter am I looking on the plug pcm side or on the transmission male terminal teeth end ? and what exactly am I looking for with the 64-124 ohm resistance?

 

[azrangerman85]

You just need an OHM meter

the intermittent light flashed after 32 miles of driving mostly stop and go 1-3rd gear . It seems to go away when I hit 40 mph -55 mph .... its intermittent and stayed off most of the day with shifts that feel smooth ... i did notice my speedometer is smoother than before the atf flush

 

[RonD]

The TSS sensor should read 64-124 ohm
Set OHM Meter to lowest setting, usually 200 ohms

OHM Meter(16 pin connector)======//========TSS sensor

The // is the connector inside the pan
Remember the exact OHMs, if it tests "in range"

Then you can unplug the PCM connector and test its 2 wires to the TSS sensor, should be the same OHMs

Pin 94 and pin 91, on PCM connector

 

[azrangerman85]

The TSS sensor should read 64-124 ohm
Set OHM Meter to lowest setting, usually 200 ohms

OHM Meter(16 pin connector)======//========TSS sensor

The // is the connector inside the pan
Remember the exact OHMs, if it tests "in range"

Then you can unplug the PCM connector and test its 2 wires to the TSS sensor, should be the same OHMs

Pin 94 and pin 91, on PCM connector

Im trying to identify the black plug on the top dead center near the rear of the transmission housing , thats what seems to connect to my speedometer

 

[RonD]

Wrong picture, thats an A4LD 1985-1994 Rangers

1998 4R44E may have an OSS(output shaft speed) sensor at top rear, but its not used for speedo in 1998 just output shaft RPMs for PCM, to make sure correct "gear" ratios are being selected

It was used as a speed sensor in 2001 and up Rangers with the 5R44E

1998-2000 Rangers used rear axle ABS sensor and GEM module for speedometer, and cruise if so equipped

 

[azrangerman85]

Wrong picture, thats an A4LD 1985-1994 Rangers

1998 4R44E may have an OSS(output shaft speed) sensor at top rear, but its not used for speedo in 1998 just output shaft RPMs for PCM, to make sure correct "gear" ratios are being selected

It was used as a speed sensor in 2001 and up Rangers with the 5R44E

1998-2000 Rangers used rear axle ABS sensor and GEM module for speedometer, and cruise if so equipped

Understood. I am factoring in everything you are informing me with . I am going to have Aamco do a drive test and scan it. Tuesday. I have been handwriting data : 32 miles od flash, 53 miles, 63 , 81 , 94 .

It flashes then goes away if I rev up and shift to 4-5th gear then clears up.... still have a hunch its dirty fluid to cycle through. Regardless of the test tueaday im draining 6 more quarts tonfinish the cycle

 

[azrangerman85]

Update :
I drove this son of a B up Black Canyon Highway Tuesday night in 90-100 degree weather . All fluid was clean and to spec level. The transmission od flashed , but I pushed it right up that steep highway climb and it held speed, power, and didnt slip. I made it from Phoenix to Prescott Valley, no overheating no smell, no binding or grinding . Aamco transmission shop are a joke!! My mission was to drive it like a test plane . Passed with flying colors. Drove it back home today and not once did a flashing light come on! my transmission fluid being dirty was the culprit, the filter has picked up any crap that caused it from remnent fluid