Unable to pull codes on 2000 Windstar

[mark_gober]

Hey everyone,

This is a repost/clarification of a previous post that I've still been unable to fix. I have a 2000 Windstar w/ 3.8L with the following symptoms:

Check engine light (was) on. (now cleared due to battery disconnect)
ABS light on. (replacing the wheel speed sensors this weekend due to torn cable)
Odometer has dashes instead of numbers(intermittently, but more so than not)
Unable to retrieve codes using a code scanner.

When I try to pull a code, it gives me a "link error" on the scanner. I've tried it many different ways, but always get the link error.

ABS light is on due to the passenger side wheel sensor having been ripped apart when a CV boot ruptured. (Don't ask how, I'm still in the dark as to how it happened) Parts are on hand and just waiting to put them in.

Odometer with the dashes. This is strange. It used to come on for about 10 seconds with numbers and then switch to dashes. Sometimes the numbers will stay for about 10 minutes and then while I'm driving, it'll switch to dashes. There doesn't appear to be any triggering cause. I've researched and found similar problems, but none that seem to be what I'm looking at. Some suggest vehicle speed sensor. The vehicle speed sensor is working because I was coasting down my street the other day and killed the engine. The digital odometer continued to tick. I've also seen leaking brake switch that is tied to the recent recall. Mine is as dry as a bone and I've disconnected it with no change in symptoms. (I also disconnected my vehicle speed sensor with no change in symptom...other than it dies after about 10 seconds of running with the VSS disconnected)

I'm really at a loss as to why I connect extract a code. With the further complication of FEM and REM, I'm not convinced about the possibility of a faulty PCM. The engine runs fine otherwise so I really don't suspect a bad computer.

Does anyone have any suggestions on how I might further troubleshoot this problem?

Mark

[Airjer_]

Check the fuses for the accessory plug/cigarette lighter. Often times the ALDL is powered by the same fuse. If the fuse is blown there will be a communication error. Most every time this happens at the shop it is because of a blown fuse.

[mark_gober]

Originally Posted by Airjer_

Check the fuses for the accessory plug/cigarette lighter. Often times the ALDL is powered by the same fuse. If the fuse is blown there will be a communication error. Most every time this happens at the shop it is because of a blown fuse.

I'll check again, but last time I checked, it wasn't blown. Correct me if I'm wrong, but if the fuse it blown, it won't even power up the scanner...correct? My scanner powers up from the DLC connector and it scans the protocols, it just never agrees on one and reads a code. It only comes back with a "link error" message.

A strange symptom that I forgot to mention in my original post is this...

If the engine is running and I plug my scanner into the port, everything goes haywire. My a/c turns on, vents go to the defrost mode. Gas gauge/speedometer go to zero. Multiple lights go on/off on the dash. Unplug it, it goes away. Not sure what that's about, but just thought I'd include it.

[road_rascal]

I think it's fuse #15 or #17. A friend of mine at work has a '99 and I couldn't get my scanner to connect either. The fuse 'looked' ok but after I replaced it the scanner worked. Go figure.

[mark_gober]

Alright...well, I've checked ALL the fuses and they are all good. I'm still getting a link error. I tried disconnecting the FEM and that didn't make any difference. Anyone have any other ideas?

Mark

[12Ounce]

Does the dash-cigar lighter work?

[wiswind]

I'm not sure if you posted in your other post about having used a friend's code reader with the same result?
If not, try another code reader.....might be something unique with the combination of the firmware in that particualr unit and your vehicle.
I am not optomistic about that as it sounds like something on that buss is hosed somehow.
As there are LOTs of things it could be, I would only be guessing if I suggest something.
Unplugging the VSS was a good idea......did you try reading the codes with it unplugged?

Perhaps a shop or dealership with their high end diagnostic tools can get you closer to a solution to this problem.


As for that torn CV boot, you don't want to drive around that way as you will get grit into the CV joint.

[mark_gober]

The cigarette lighter does work. I got under there with a multimeter and all of my voltages appear fine. I checked each and every fuse and they were all fine, both under the dash and under the hood. The pins at the DLC have voltage where they're supposed to.

WisWind, I did, in fact, try to use another code scanner and had similar results. It simply cycled through the protocols and then said "unable to connect". The more I mess with this, the more I feel like I've got a bad PCM. I've disconnect the FEM and had no change.

One thing I'm going to try....I have a 99 Windstar that my brother's father in law siezed the motor in. (long story) We bought it for $100 to use for parts. (Which I've more than made my money back on). I'm going to swap out the PCM from it and see if I can connect to it. I suspect I'll be able to. If so, I know I have a bad PCM module. If not, I can always try to isolate the problem component by disconnecting modules/sensors from the PCM.

I'll keep everyone posted on what I find.

Mark

[12Ounce]

I would be hesitant to try a different PCM. When the PCM, the instrument panel, the key transponder ... are all three first fired up, they go through a self initialized "marriage" ... the keys are coded in the same process. As I understand it, if any of the three components are replaced, it takes a special service tool to make the three "bond" ... and new key codes may be also generated. Not a simple process.

I suspect you have harness/wiring issues ... give me some time and I will get the shop manual out and see if I can come up with some useful info.

A number of the '99 and '00's had PT harness damage due to chafing.

[mark_gober]

Originally Posted by 12Ounce

I would be hesitant to try a different PCM. When the PCM, the instrument panel, the key transponder ... are all three first fired up, they go through a self initialized "marriage" ... the keys are coded in the same process. As I understand it, if any of the three components are replaced, it takes a special service tool to make the three "bond" ... and new key codes may be also generated. Not a simple process.

I suspect you have harness/wiring issues ... give me some time and I will get the shop manual out and see if I can come up with some useful info.

A number of the '99 and '00's had PT harness damage due to chafing.

12oz.,

Thanks for the assistance. I have an Alldata account, but unfortunately, it simply doesn't get that in depth in the OBD arena. I can get pin numbers and wire colors etc., but I'd like to know what is actually happening or a troubleshooting strategy.

On a related note, I didn't read your post yesterday and I pulled the PCM out of the 1999 Windstar. Good news is that even with the new PCM in, I was still unable to connect. That confirms to me that it's not the PCM causing the issue. Additionally, when my PCM was returned, the car fired right up. Interestingly, the car would not start with the replacement PCM in it. I am sure this is due to the PATS key code issue. I really wasn't interested in getting it to start, I simply wanted to see if I could retrieve codes from it.

I have disconnected the FEM before and was unable to retrieve the codes. I'm going to try disconnecting the REM and see if that makes any difference. If it doesn't (I don't think it will), I'm going to disconnect the various sensors/modules that are shown to be connected to the PCM and attempt to retrieve a code again. I'd certainly appreciate any shop manual advice that you can offer.

One thing I thought about doing was to disconnect the PCM harness and create a makeshift harness just into the wires that I need to connect to. (power, +bus, -bus) The other side could connect to my scanner and see what I get. That would determine whether the factory harness is causing the problem or not. (Don't worry, I'm an electronics technician by trade, so I'm not worried about shorting anything out)

One final question...I've had other cars that had both the OBD connector under the dash and an additional "diagnostic" connector under the hood. I believe that when I get my car inspected, they are connecting to the one under the dash. Does the Windstar have that second connector? I've looked and can't find it. Does that mean that the inspection place just connects under the dash?

[wiswind]

My '96 only had the 1 connector, the one you have been using under the dash near the steering wheel.
My '03 Sienna has "several" connectors under the hood in addition to the one under the dash.

[12Ounce]

Sorry it took me so long to get back to you on this. Too many libations over the holidays!

I think there is only one connector ... and it is referred to as the Data Link Connector. (DLC).

I'm assuming you do not have the wiring diagram. ?? I will give you a bit of info here ... and with a long jumper wire and volt/ohm meter we should be able to sleuth something out. You will have to remove the windschield cowling to get access to the powertrain harness and the PCM connector. Inspect the harness for chafing against the firewall and then lets check for conductivity thru the harness to the DLC. Be sure to have battery disconnected for the ohm readings.

Looking at the DLC:
.pin #4 and pin #5 should have a black conductor and each should be grounded.
.pin #13 should have VT conductor landing on pin #13 of the PCM connector. I think this is a dedicated conductor .... goes no where else ... and should "read" accordingly.
.pin #16 LB/WH ... 12 volt supply from fuse #17 ... also feeds cigar lighter.
.pin #7 ... also LB/WH (unfortunate) but a different conductor from the one above ... feeds restraint control modules, sliding doors, parking aide module .... chassis stuff. I don't think there will be any "logical" problem with this conductor.
.pins #2 and #10 ... these have the "twisted pair" that do all the communication thru out the vehicle ....
...pin #2 TN/OG, to pin #16 PCM, pin #16 instr cluster, pin #3 Rem Key Entry module, pin #1 REM, pin #7 FEM, pin #1 speed control module, pin #17 anti lock brke module.
...pin #10 PK/LB, to pin #15 PCM, pin #17 instr cluster, pin #4 Rem Key Entry module, pin #2 REM, pin #1 FEM, pin #2 speed control module, pin #6 anti lock brke module.

Good luck

[mark_gober]

Originally Posted by 12Ounce

Sorry it took me so long to get back to you on this. Too many libations over the holidays!

I think there is only one connector ... and it is referred to as the Data Link Connector. (DLC).

I'm assuming you do not have the wiring diagram. ?? I will give you a bit of info here ... and with a long jumper wire and volt/ohm meter we should be able to sleuth something out. You will have to remove the windschield cowling to get access to the powertrain harness and the PCM connector. Inspect the harness for chafing against the firewall and then lets check for conductivity thru the harness to the DLC. Be sure to have battery disconnected for the ohm readings.

Looking at the DLC:
.pin #4 and pin #5 should have a black conductor and each should be grounded.
.pin #13 should have VT conductor landing on pin #13 of the PCM connector. I think this is a dedicated conductor .... goes no where else ... and should "read" accordingly.
.pin #16 LB/WH ... 12 volt supply from fuse #17 ... also feeds cigar lighter.
.pin #7 ... also LB/WH (unfortunate) but a different conductor from the one above ... feeds restraint control modules, sliding doors, parking aide module .... chassis stuff. I don't think there will be any "logical" problem with this conductor.
.pins #2 and #10 ... these have the "twisted pair" that do all the communication thru out the vehicle ....
...pin #2 TN/OG, to pin #16 PCM, pin #16 instr cluster, pin #3 Rem Key Entry module, pin #1 REM, pin #7 FEM, pin #1 speed control module, pin #17 anti lock brke module.
...pin #10 PK/LB, to pin #15 PCM, pin #17 instr cluster, pin #4 Rem Key Entry module, pin #2 REM, pin #1 FEM, pin #2 speed control module, pin #6 anti lock brke module.

Good luck

12 oz,

Thanks for the info. I actually do have the schematics. I have an Alldata account. Before I get into what I'm going to try, I want to ensure your info is correct. I believe that it is, but in my Alldata account, it is different. Please review the diagrams that I've attached. On mine, the wire colors/pins jibe with what you wrote (only at the DLC connector). Look at the A, B, C triangles at the top of the DLC diagram. If you follow them to their respective locations, the colors switch. Pin 7 goes to triangle A (which is LB/WH.) If you go to the file called "First set of modules", triangle A is TN/OG. Pin 2 at the DLC is triangle B. If you follow it to the same "first set of modules", triangle B is LB/WH. Triangle C matches.

Due to the difference on my drawing, I question Alldata's site info. What did you pull your info from?

Now that that's out of the way, let me run by everyone what I'm planning to do next. I thought about disconnecting the various modules also connected to pins 2,10 on the DLC connector and then attempting to connect directly to the PCM. If that proves way too difficult, I pondered taking four wires and fashioning up a makeshift cable to go from my scanner to the PCM. I could disconnect the harness at the PCM and just place my four wires directly on pins 15,16 (bus) at the PCM. And run one to ground and one to the 12v. That would eliminate everything except the PCM. That eliminates cables, and other modules sharing that twisted pair.

Any thoughts?

[12Ounce]

The diagram graphics you have are exactly the same ones I have in my paper manual ... complete with the confusing errors you point out about the "triangles'. My manual is now loaded with pencil markings where errors have been discovered, some have been worked out and corrected. (For example, in the power window section ... my manual has no left front window motor. Yours may be the same.) How did so many errors get published? I suspect, the electrical engineer handed over his notes to a draughtsman ... and never checked the work.

I understand your work-around wiring scheme ... but I wish you would first visually/electrically inspect the harness as I have proposed.

[serge_saati]

Originally Posted by mark_gober

Check engine light (was) on. (now cleared due to battery disconnect)
ABS light on. (replacing the wheel speed sensors this weekend due to torn cable)
Odometer has dashes instead of numbers(intermittently, but more so than not)
Unable to retrieve codes using a code scanner.

Like I told you one time, the odometer problem is more likely resulted by a bad "instrument cluster". This a 10 years regular maintenance on your Windstar since your gauges can come crazy one time and stop working. It'll be prevent further gauge/cluster problem.

For your link error problem, have you tried it before you reset the battery?
If you try to retrieve codes after they've been erased, of course it'll tell you "link error". Your PCM's frames are still frozen. You need to drive a while before PCM relearn everything, detects the problem(s), CEL come on and you'll be able to retrieve the codes. Or it's a problem with on of these modules.