Persistent P0715

Hi all,

I've learned a lot about our 'new' Windstar from reading through these forums, and now I have a ? about a code I can't seem to get rid of. First off a little background on the Windstar. It is a 1995 GL model, 3.8L. I purchased it for $400 with a 'blown' engine, body is in great shape. After replacing the water pump, head gaskets, and cleaning a lot of sludge out of the engine it has been running great. The only issue I'm having is the P0715 code that I can't get rid of. Sometimes I will get the code right away after clearing it, at other times I could drive 100 miles without it. I've cleaned the contacts on the turbine speed sensor and the harness plug, but still no luck. I'm leaning towards an intermittant connection somewhere, probably a broken wire in the harness. Next steps for me are to check the sensor itself for any output, and if the sensor is good just run a pair of new wires from the sensor up to the PCM harness. Am I barking up the right tree here or is there something else I can look at?

I believe there is a P0718 code for intermittent TSS conditions.
There are some Ford bulletins regarding P0715 codes, but I do not have access to them. You might want to see what's going on in that info before doing any mods.
Other than that, sounds like it’s the TSS, Wiring, or PCM.
I'd look at the freeze frame data to see what the conditions are for setting it. Then see if it is meeting the conditions below:
Turbine Shaft Speed Sensor Functional Check Operation:
DTCs P0715
Monitor execution continuous
Monitor Sequence none
Sensors OK
Monitoring Duration 30 seconds
Typical TSS functional check entry conditions:
Auto Transmission Entry Conditions Minimum Maximum
Gear selector position - drive
Engine rpm (above converter stall speed) OR 3000 rpm
Turbine shaft rpm (if available) OR 1500 rpm
Output shaft rpm 650 rpm
Vehicle speed (if available) 15 mph
Torque converter lock-up (some applications) 3rd gear only
Typical TSS functional check malfunction thresholds:
vehicle is inferred to be moving with positive driving torque and TSS < 200 rpm for 5 seconds
Sorry, I have no more clues.

Just following up on my post about the P0715 I couldn't get rid of. I probed into the wires and was getting a signal, so I figured it must be a problem in the wiring. I spliced some 18ga wire into the harness at the sensor, then ran the wires all the way up to the PCM where I spliced them in. It probably wasn't both wires, but I didn't feel like messing around figuring out which one was the problem. Started the van up and the MIL light was off, plugged in the code reader and no codes. Ford and their wiring harnesses... Other family members that own Fords have had issues with the wiring, so I guess I'm part of that club now! Thank you for your reply Huskerdooo!