Sordid Tale of a "Service Engine" Light

Maintenance/Repairs
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281

Sorry to hear that Matthew. That has to be very frustrating. While I doubt that it was programmed wrong, there may have been a problem with the fuel pump or ignition circuit inside the PCM, who knows!? At least you were able to return it. Did you order another replacement for it?

As far as the radio problem goes there may be a problem with the grounding to it. If it looks like the radio shows signs of loosing power to it then it may be a faulty ground to it. There may be a seperate amplifier module for the system also and the problem is with it for the same reason.

The coolant and seatbelt lights may be coming on due to a problem with a ground or the alternator may be acting up. See if reving the engine helps turn them out when they turn on. If they do go out then it may be alternator but it could be the grounding also.

282

I did not reorder from that particular store, but Iā€™ll have to from another nowā€¦

Note that with the radio, the digital display always works, itā€™s just the sound (same with CDs). So, an amplifier module would make sense to me.

The seat belt and coolant lights only come on for 2 or 3 seconds at a time, not enough time for me to figure out a patternā€¦ But Iā€™ll keep trying.

Iā€™ll look for the grounding wires for both issues.

283

http://www.autozone.com/shopping/repairGuide.htm?pageId=0900c1528003a892

284

I found someone who had the exact same problems (plus a few more) with the steering/seat belt light/etc.: http://www.taurusclub.com/forum/index.php?showtopic=31979

It sounds like the TR sensor, aka the neutral safety switch: http://www.autozone.com/shopping/repairGuide.htm?pageId=0900c1528003ad5a . Iā€™ll check it out and play with it before I replace it tomorrow.

285

Testimonials can be useful when, "applied in a conscientiously approved manner, with appropriate thought given to how the conclusions were reached by the testimonialist."
Was the Ford Article No. 98-23-12 (ref. my post on 09/24/2008) supportive of the testimony, or vice versa?

286

Given that all things are not equal, supportive.

I admit, I let your post slip by without giving it the consideration it deserves. I apologize.

287

So, there is moisture in the TR sensor connector itself. Along with liquidy blue stuff (from corrosion?) around the pin holes. The entire sensor is covered in greasy grime.

This would explain why sometimes if I drive through a big puddle, the steering wheel would tighten up. It has done this for years (so Iā€™ve avoided puddles).

288

Good find there Matthew.

289

Yes, Iā€™m glad you found something pretty definitive in your troubleshooting. Maybe, now, we can get somewhere!
If you look at the PCM wiring diagram, youā€™ll see that there are seven (7) wires (circuits) that go between the transmission and the PCM.
From the alldata > Vehicle Level > Diagrams > Connector Views > Engine Control Module< , is the PCM connector chart which shows all the pin numbers, circuits, wire colors, and describes the circuit functions.
For example: pin 1 is circuit 315, wire color is pink/orange, and itā€™s circuit function is, ā€œShift Solenoid #2ā€.
Pin 27 Shift Solenoid #1 Control circuit
Pin 29 Transmission Control Switch circuit
Pin 37 Transmission Fluid Temperature Sensor Input circuit
Pin 53 Shift Solenoid #3
Pin 54 Torque Control Clutch Solenoid
So, you can see that the inputs from the transmission, and the outputs to the transmission can have quite a number of affects. The alldata has troubleshooting charts for the transmission circuits, also.

The problems with the first replacement PCM may have been caused by the Transmission Range Sensor. We wonā€™t know, now. Too bad.

Changing the Transmission Range (TR) Sensor may cure everything except the oxygen sensor heaters. Dream of success!

290

I agree,I think it will fix everything but the O2 problems as well.

Hereā€™s a big update, where do I startā€¦

I ordered and received a new TR sensor for Autozone. Brought it home, took out the old one, and immediately realized that they sold me THE WRONG ONE. The one they gave me was a 10 pin, the one in my car is an 11 pin. My original TR sensor is also significantly larger than the new one. I called them back, and after explaining everything, they double checked and confirmed that they did not have that part. They said that the 97 model did have an 11 pin thoughā€¦ I said thanks but no thanks to thatā€¦ (never mind, bad joke). I called around other places, and either no one had it, or they could not confirm for me if what they could order was 11 pin or not. I tried calling the Ford place all day long and had to leave a message. At this point, I will go ahead and order one through Ford after I am convinced that they know exactly what I need. Unless it costs hundreds of dollarsā€¦

Here is what I think the underlying problem is that would explain this, and possibly the PCM I bought and did not work: For some dang reason, few auto-parts places know what a 1998 Ford Taurus SE is. Emphasis on the SE. What I mean is, the ā€œSEā€ model is not in their databases. Damned if I know why. So, they assume it is the same as the LX because the LX apparently has the same engine and what-not. So, I think that I have a rare vintage of La Taurus that is throwing them off. That mistake will NOT be made again.

My old TR sensor has a lot of moisture in it. Iā€™m too afraid to take it apart to clean it out for fear of braking something because this is my only car. But what I DID do is take sandpaper to the dirty pins and shined them up nicely. I also took a hair dryer to the connectorā€™s pin holes to dry it out. I drove it a good deal after that and the car did just fine, no problems. In fact, there were only a few shifting problems at first, but that IS typical when I disconnect the battery for a while. Though, from my reading, I did not think that this would affect it staying in gear. Hell, I could remember wrong.

EDIT: And, AND, I was specifically told on the phone that ALL of the taurus models for that year took the same size TR sensorā€¦ Shows what they know.

I highly, highly doubt that the TR sensor was affecting the new PCM. Only because with the new PCM the car would not start at all, it would just keep trying to turn over. One good thing is that I have NEVER had any problems starting the car (in park or neutral).

I canā€™t afford to order a new PCM through Ford ($500!), so I will try again at another place that I am convinced understands what I need. Worst that will happen is I get my money back.

291

None of my information sources show an SE sub-model. Few would know the difference between an LX and an SE. ADDED: Learned from Parts that the catalogs donā€™t show SE; that SE (ā€œSpecial Edition*ā€) just denotes a trim package. I understand that your car has a SE badge on it; but, other than the trim package, itā€™s still an LX.
Here is a parts listing for the neutral safety switch (which Ford calls a digital transmission range sensorā€¦six of one, a half dozen of 'nuthern). Some have 11 pins. http://www.partsamerica.com/ProductList.aspx?PartType=401&PTSet=A
Dirty grease/oil can cause a short with some resistance; so, itā€™s not a ā€œdead shortā€; but, a short none the less.
Use a non-oily spray cleaner (brake cleaner, contact cleaner, ether) to thoroughly soak the transmission range selector (neutral safety switch) and its electrical connector(s). then, sprayā€™em again. Let dry a few minuets. Giveā€™er a run. Results?

292

I also very much doubt the replacement PCM was effected by the TR sensor.

293

You know what the part looks like. Call the parts store. Go and look at what they have. You should find a match.
The Ford Article on the TR Sensor has some voltage checks to run with a (Ford only?) scan tool. This alternate way may work: Backprobe PCM 91 and PCM 64. First try it with the red probe of your multimeter on PCM 64, and black on PCM 91. If that doesnā€™t work, put the black probe to ground.
Desired test results: with ignition ON (RUN) transmission in PARK, 0.0 volts dc. With the shift lever Reverse, Neutral, Overdrive 1.3 to 1.8 volts dc.
If all the positions are 0.0 volts; then, that shows a short to ground. If 9 to 14 volts, thereā€™s an open circuit. If 1.8 to 5 volts, itā€™s caused by an open circuit or a bad resistor in the DTR Sensor.
While checking the Park position voltage (desired: 0.0 v.) wriggle the wires to the TR Sensor. If voltages come and go, wriggle the wires down to the problem area.

294

Iā€™m still hereā€¦ I went on vacation and thought Iā€™d have internet access. I was wrong.

If I had another car, I would definitely brave taking apart the neutral safety switch and clean it because Iā€™m quite sure that nothing is broken, just wet and grimy. BUT, I donā€™t. I want to replace it because water just seeps out of it and even after cleaning the pins, a day or two later they are back to being corroded. I called Ford, gave them my VIN #s and the number off of the sensor itself. Went to pick it up, and knew right away it was the wrong one. So, I took the old one out and brought it into the store. They placed another order and I should get it today.

When I clean the pins on the switch/sensor, the car drives just fine. So Iā€™ll be able to finally relax once I get that part. Then Iā€™ll concentrate on the PCM again.

Thatā€™s really good news about the models hellokit. I guess it would also make sense because the car has leather, a 6 disk changer, and power everything. Thereā€™s actually a SES model as well, though I have no idea what else they could have includedā€¦ maybe a sunroof? Anyways, then that makes me feel better about ordering a refurb PCM again.

You guys have been great, thanks again for having the interest and patience required to stick with me through all of this, I have learned a lot.

295

SO,

Yesterday I finally got the correct Neutral Safety Switch. Now it runs like a brand new car.

Today I will once again order a PCM, but from a different place this time.

296

That is good news Matthew. You are finally making progess on this ā€˜sordid taleā€™.

297

Why donā€™t you scan the PCM (engine Computer), first. Make sure it still has DTCs for the oxygen sensor heaters. Itā€™s not impossible for that to have changed, too.

298

It IS good news!

I scanned this morning. Which means the new switch has had about 20 miles on it now. P0135, P0155 and P0455 (still with that large leak!) popped up.

I can always clear the codes. I guess I will next time Iā€™m in it.

299

Yes, you need to ā€œclean the slateā€ with the new transmission selector sensor installed. The codes in there now are probably from the time before the change. Eraseā€™em and see.

300

I did that yesterday. Since then codes have come back: P0135 & P0155 are ā€œstoredā€ and P0455 is ā€œpending.ā€

That P0455 worries me. Is it probable that my bad PCM is causing that code as well? I hope so, because Iā€™ve replaced all of my little hoses and my big hoses all look good. Gas cap is fine. I even put an extra hose clamp at the PCV because it was not sitting snug in the larger hose.