Hi there,

I am in the process of repinning my 1997 C5 to accept an 12200411 ECU.

On the 1997 PCM Pinout list, Document 212597, Powertrain Control Module (PCM) Connector End Views, it lists Red Connector Pin 13, Circuit 2122, PPL/WHT as Injector #2 Control.

It also lists Red Connector Pin 23, Circuit 1745, LT GRN/BLK as Injector #2 Control.

It looks like the 21** circuits are all the ignition controls, and Pin 49, Circuit 2121, PPL is Ignition #1 Control, and this would go along with the Color - Color / Wht scheme for the rest of the injectors. Easily figured out, I guess. Frustrating that an official GM document would be wrong.

That is not my problem though.


My problem is in the 2002 PCM Pinout List, Document 772993, Powertrain Control Module (PCM) Connector End Views, it lists the following:

Red Connector - Pin 26 - Circuit 2121 - Wire PPL - IC 1 Control
Red Connector - Pin 67 - Circuit 2122 - Wire RED/WHT - IC 2 Control
Red Connector - Pin 69 - Circuit 2123 - Wire LT BLU - IC 3 Control
Red Connector - Pin 29 - Circuit 2124 - Wire DK GRN/WHT - IC 4 Control
Red Connector - Pin 68 - Circuit 2125 - Wire DK GRN - IC 5 Control
Red Connector - Pin 28 - Circuit 2126 - Wire LT BLU/WHT - IC 6 Control
Red Connector - Pin 27 - Circuit 2127 - Wire RED - IC 7 Control
Red Connector - Pin 66 - Circuit 2128 - Wire PPL/WHT - IC 8 Control

The 1997 PCM Pin out lists the following:

Red Connector - Pin 49 - Circuit 2121 - Wire PPL - IC 1 Control
Red Connector - Pin 13 - Circuit 2122 - Wire PPL/WHT - IC 2 Control
Red Connector - Pin 58 - Circuit 2123 - Wire LT BLU - IC 3 Control
Red Connector - Pin 57 - Circuit 2124 - Wire LT BLU/WHT - IC 4 Control
Red Connector - Pin 56 - Circuit 2125 - Wire DK GRN - IC 5 Control
Red Connector - Pin 54 - Circuit 2126 - Wire DK GRN/WHT - IC 6 Control
Red Connector - Pin 53 - Circuit 2127 - Wire RED - IC 7 Control
Red Connector - Pin 52 - Circuit 2128 - Wire RED/WHT - IC 8 Control

Why would the wire colors be different between the two years? Why would they swap 2<->8 and 4<->6 on the 2002?

My problem is that I'm trying to correctly pin the connectors and this seems confusing. If there was an error in the 1997 document, there could be errors in the later documents. I've tried looking at my coil packs but the wires are covered in 25 years of grime and are faded to not accurate colors.

Thank you!

 

That’s probably a question for GM’s Electrical Engineers who designed and built the circuits on the C5…that’s why it’s important to at least list your model year in your profile if having issues…wiring changes, some ground locations change etc…I’ve found a few mistakes in the FSM electrical diagrams and ones used by Mitchell and ALLDATA.

 

check out this site: This guy is pretty much an expert on GM PCM’s. https://lt1swap.com/wiringharness.htm


the 411 PCM us used in many chev and GMC trucks that have the 5.3 and 6.0 engines. He has a pin out table on his site. Also, he is good about responding to emails,

 

Thank you so much!

 

Thank you!

 

Be careful what you delete

 

Got it figured out. Just went with circuit #s to match.

I'd post a video but I don't know how; will figure it out later.

I'll also post my spreadsheet as well.

 

I used a 1997 and 2003 Factory Service manuals and all colors and circuit numbers matched. I had 3 or 4 ground wires left over that did not make any difference. Car runs perfectly but am having fuel gauge issues but believe I have found a cure for it.

 

Use these as a correction

 

How did you program the new PCM? Did you use the original car VIN or another year model?

 

My 12200411 is from a 3500 silverado.

I purchased a "bench harness" from eBay and purchased an OBDX Pro VT dongle. I downloaded PCM hammer on to my laptop. I acquired a BIN from a 2001 base MT C5 from a friendly person on the internet, which was with operating system 12593358. This BIN came with VATS deleted and CAGS removed.

I got everything set up on my bench and read the used 12200411 information woth PCM hammer, flashed my existing VIN on to it with PCM hammer and then flashed the PCM with the internet BIN with PCM hammer. Then I plugged it into my car and it fired right up. Amazing eh?

All it it was like $150 for the dongle, bench harness, PCM and a donation to those programs mentioned above.

Next, I'll be disabling the AIR system with TunerPro and flashing that on to the car.