16144288 TBI ECM upgrade to 16168625 TBI PCM

[57 Handyman]

Thanks Dave, I just ordered it. It should arrive in a week.

[57 Handyman]

OK, received my connector order from Mouser today. Now, I'm ready to start re-pinning. As I understand, I am removing pins with harness wires from my 4288 ECM connector and inserting them into the locations in the new connectors for my 8625 PCM. Basically, according to the information in the thread "1227747 to 16197427 Conversion PCM Swap with Wiring Pinout Directions!", pin A1 from the old connector goes into F6 in the new. Correct?

Do you have any suggestions on the best tricks to follow? Should I mark and label each wire? What else?

[dave w]

Your are correct with the process of moving the connector pins, A1 is moved from the old connector to F6 of the new connector.

Be patient, sometimes the pins can be stubborn to remove. Having new pins available is a good plan, just in case a stubborn pin is damaged during the removal process and needs to be replaced. The first time I did a conversion I labeled everything. I made masking tape "Flags" to label the wires. I used black ink to label the old connector pin number, then used either blue or red ink on the other side of my masking tape "Flag" to indicate the new connector pin. I used blue ink for the blue connector pins, and red ink for the red connector.

Double check and triple check the connections, before starting the engine.

dave w

[57 Handyman]

Ah....good idea! That is the kind of tips I definitely need to NOT mess things up.

So do you think the current BCC BBMW in my 8625 will suffice for start up purposes? What do I also need to do regarding the notes?

Thanks for your help thus far Dave...it really is nice to have helpful and knowledgeable folks to guide newbies like me along.

[57 Handyman]

Dave,

Today, I followed your suggestion to flag each wire on the 4288 ECM harness with old and new locations in black and red or blue ink, respectively. Interestingly, I found some variances between the listing and my ECM harness. In a few instances, there were no wires in the locations due to the function(s) not being available on my S10, i.e., Charcoal Canister Purge Solenoid (A3), A.I.R. Converter/Port Solenoids (C1 and C2), Power Steering Pressure Switch (C8), MAT (don't know what this device is) Signal (C12), and Injector "2" Control (C15/D14)...OK no problem! In 1 or 2 instances, there were wires of different color and guage.

In general, what do I do with pins and wires which I do NOT need? Do I just move them to the side and tape the pins and bundle them?

With regard to the Swap Notes:
1* I have a 700r4 but no TCC light so what do I do with this wire?
2* Have no clue what I should do.
3* My 4.3L does have a single wire Knock Sensor. Do I re-pin this B7 (red)?
4* No wire and no A.I.R.
5* My S10 is a automatic 4x4 and there is a high/low gear switch. What do I do?
6* No problem...no wire.
7* What is meant by "store in small connector?"
8* No problem...no wire.

When I re-pin the harness and install/connect the PCM 8625, what happens to the ALDL...will it still function? How do I get codes and will the Check Engine Light still work? And lastly, just out of curiosity, what kind of on-board diagnostics (OBD) will I have?

Thanks.



I double checked the flag notations and will make another pass tomorrow. After that, I will prepare an exact listing and post it.

[dave w]

I have some of the information you are requesting.

Several years ago, members from Thridgen.org posted information on upgrading the Camaro TBI to the red / blue PCM. The S-10 and full size pickups have a similar wiring harness like the TBI computers.

The TCC wire goes to Pin E11 ( there is some PCM upgrade notes floating around the internet that are not correct about the TCC wire location, use Pin E11)

Most, maybe all red / blue PCM's will have only one knock sensor wire that goes from the knock sensor directly to the PCM *B15*. I'm thinking your S-10 has an ESC module with a wire coming from the knock sensor that is connected to the ESC module and wire going from the ESC module to the old computer. I solder the two knock sensor wires that are at the ESC module to made one continuous wire going from the knock sensor going directly to the PCM *B15*.

There is a "Whole can of Worms" when it comes to figuring out what knock sensor or knock sensors to use when you upgrade to the red / blue PCM with the 4.3 engine. If you were upgrading a 5.7 liter V8, then you would be able use Standard Motor Products knock sensor KS6. Maybe you can use the KS6 part number? I don't know. I think some 4.3 liter V6 engines use two knock sensors, one in each head. You will need to do some "Homework" to figure out the actual part number or part numbers needed for the 4.3. I don't know the exact Make, Model, Year (engine / transmission / engine VIN Code) of the vehicle for the knock sensor you need. I'd start looking at S-10 Blazers and Pickups with the 4.3 liter TBI engine from 1993 ~ 1995 that used the red / blue PCM, with the 4L60E transmission. It's very possible you will need to two knock sensors, and will need to use the wiring diagrams to figure out how to wire them to the new red / blue PCM. Homework, Homework, and more Homework! There is the option of deleting the need for a Knock Sensor in a custom PROM chip, not sure that is a good option?

The orange Serial Data wire needs to be relocated from the top row, Pin "E" to the lower row, Pin "M". You will need only 3 wires in the ALDL, "A", "B" and "M" the others wires you have remaining in the ALDL need to be removed.

For the high gear switch wire, or for any wire that is not needed, I terminate the wire by double covering the connector end with heat shrink tubing. I extend the shrink tubing about 1/4" beyond the end of the unused connector. I place the unused wires in a safe place with a zip tie.

dave w

[57 Handyman]

Dave,

Just checking back in with an update:

Somewhere in all the reading I've done, someone mentioned that they made an old-to-new adapter which allowed them to initially keep the old connector while finalizing the tuning activities. Since I also had an extra ECM, I cut out the male-end and will connect the terminals to a red/blue pigtail I found on eBay. I plan on using each of the recommendations you've provided thus far. Do you think the adapter may interfere with and make tuning more difficult?

With regard to the knock sensors, I found some info about using one or two sensors but like the question about which one, there is nothing definitive. More than likely, solving this issue will be one of those trial and error solutions. Since I just returned from an out of state trip, I haven't checked out the ESC module to address what goes to PCM B15. Once I confirm the ESC and wire color, I'll be better prepared.

Lastly, what would be your recommendation regarding when to rewire the ALDL? Do you know if the use of my adapter (described above), negate the functioning of the ALDL altogether?