OBD non-connection error

[CheeseHelmet]

Ok here's what we got:

• DLC PIN #01 > ROOM fuse: GOOD
• DLC PIN #04 > PCM PIN #13: GOOD
• DLC PIN #10 > PCM PIN #79: GOOD
• DLC PIN #12 > PCM PIN #77: GOOD
• DLC PIN #13 > PCM PIN #77: GOOD

New ECU is in order I'm assuming??

Heh, I clicked on the link in my email before and there were a few "NO CONNECTION" marks in your table. Dirty terminals giving you false negatives?

If the wiring is good then it looks like you'll need a new ECU, it's a shame it wasn't something simple...

 

[LardOfTheDance]

Thanks CheeseHelmet for all your help. Its a shame, probably had this problem all along and never knew about it because we've been in FL where the inspection is not required.

To answer your questions, I ran the tests initially and came back with some negatives. Went in to eat a sandwich for lunch and said, "Hey you know what? Maybe the probe on the tester is just a little too wide to get in there and make contact with the pins." So I rigged them up with some make-shift aluminum foil pointers on the end. Sure enough that dial started swingin'. So I rushed back and changed the post.

Time to face the music now tho. Let's hope I can find one for reasonable price. =(

 

[DarkAngel]

Depending where you look for one being Ebay, Junk yards you can find one for a decent price. I just checked ebay and there are several there.

As long as it is an ecu from 01-03 for a 2.0 and depending Auto or Manual you should be good. Heck you can even upgrade to the MP3 ECU if you wanted but only if you are manual.

 

[LardOfTheDance]

Quick ECU part number question....

Here's a graphic from the parts catalog. It looks like I have two possible part numbers. I need to know if it makes a difference or not b/c local junkyards are asking me for a specific part number.

What is the difference between following:

• FS7N-18-881D
• FS8L-18-881C

 

[CheeseHelmet]

What page of the parts manual is that from?

 

[LardOfTheDance]

4-m 8

 

[CheeseHelmet]

4-m 8

The last column (not shown in the picture you linked to) should give you the right answer, it contains VIN ranges for each of the 3 possible manual ECUs with "sport suspension". If you want to be absolutely sure, give your local Mazda dealer a call and see if they can look up the part number for you using your VIN.

That being said, any ECU from a manual protege5 should do the trick...

 

[LardOfTheDance]

Thanks again for the insight!

 

[LardOfTheDance]

PCM replaced

Thanks to Cheesehelmet for the guidance and Duffbuster243 for the part (an easy transaction).

This took about 20 minutes to do. My friends cheap little OBD II reader made a connection and there were no codes!

Tomorrow we take it in for inspection hopefully we can close this chapter.

Final update (hopefully final) tomorrow or Wed.

 

[Iresqu1]

This happened to me on my suburban, found to be the lighter fuse. Turns out the lighter and obd port are powered by the same fuse.

 

[LardOfTheDance]

Not quite final update

So new ECU is in and last night drove it around for an hour or so. The car ran real funny. Especially in 1st gear. At 2500 RPMS the car started really bucking. 2nd was a little wonky but less than 1st. By the time I was getting to third it was fine.

After driving it a round for a while, low and high speed, a few re-starts, it seems to be stabilizing. This morning there was no bucking and shifted smoothly.

I'm just guessing from piecing together some research that it has something to do with a "drive cycle."

For this reason i'm going to drive it around a few more days before i take it in for inspection just to be sure.

Comments??

 

[CheeseHelmet]

It could be something unrelated (like a flaky EGR valve) or it could be that the ECU is still adjusting to your car's sensors.

You said your buddy has an OBDII scanner, you should scan your car before going for the test. The ECU has a bunch of "readiness" indicators for all the different emissions subsystems, the scanner will report the status of each of these subsystems. You'll get one of 3 results for each one: "ready", "not ready", or "not available". If you get "not available" for a particular subsystem, just ignore it as it doesn't apply to your car. If you see anything that's "not ready" you need to drive the car some more (at least 2 drive cycles). After doing that either it will either be "ready" or you'll have a DTC stored in the ECU.

A proper description for a drive cycle can be found at the beginning of the service manual, but in my experience a good 10 minute drive on the highway at constant speed works fine. Depending on the subsystem being tested, you might have to let the engine cool off before doing another drive cycle. Your plan of doing a few days of normal driving should work perfectly

 

[LardOfTheDance]

It has been accomplished!

I believe we can close this thread . . . ( thanks for all the help )

 

[CheeseHelmet]

Congrats!

The pic if anyone is curious:

 

[DarkAngel]

Good to see you fixed it and the ECU was the problem.