p0715 sensor replacement / almost stalling at stop

[1991Syclone]

Van: 2006 Mazda5 Sport AT

A few weeks ago I had the P0715 code come up and the van dropped down to 3rd gear until I stopped. After searching through the forums I found that the turbine speed sensor should be replaced to fix the issue. I replaced it this past weekend along with the rear shocks. Not too bad of a job. I noticed today that when slowing to a stop the van appeared to hold 3rd gear longer than usual (although I've never really paid attention to how long it stayed in 3rd before).

As I slowed, the van started to shudder like if you had forgotten to push in the clutch on a stick shift car. Then for a brief second the code warning light (the yellow one that looks like an engine) came on along with the battery, the shut off immediately as the idle came back up. It happened once more on my commute as I came to a stop for a red light. I did notice an unusual amount of corrosion on the negative battery post when I was taking it out and cleaned it off as best I could.

I'm wondering if I need to re-clean the negative battery cable better and if it could be related to the almost stalling. I just find it coincidental that it happened right after I replaced the speed sensor. Anybody else have this issue? I did a search and came up with one thread about having the ECM reflashed, but I never had this issue in all the time I've had the van (since 13k miles and I have 156k on it now)

Any help is appreciated

 

[1991Syclone]

It looks like I've fixed the issue. One thing I didn't read in the threads about the sensor replacement is to do the idle learn procedure after disconnecting the battery. Maybe it's common knowledge and I just didn't think about it. But here's what I did at lunch yesterday and everything seems fine now:

1. Turn the ignition ON without starting the engine, for one minute, then turn the ignition OFF.

2. After waiting one minute, start the engine.

3. Warm the engine at idle until the cooling fan starts operating or until the coolant temperature reaches 194 degrees F or higher.

4. Turn off any electrical load, including the A/C, with the shifter in neutral or park.

5. Let the engine run for five minutes.

No issues on the ride home last night or this morning.