Transmission control module connector?

Tiny
JAMESB2019
  • MEMBER
  • 2006 PONTIAC G6
  • 3.9L
  • V6
  • 2WD
  • AUTOMATIC
  • 150,000 MILES
This car listed above has an ISS code 717 even after replacing the ISS. I suspect TCM, wiring or connector problems. Although there maybe something wrong with the shift solenoids or Valve Body, I am going to test and replace the connectors first. The problem is that I could not find a new 49-way TCM connector (I suspect the current one isn't right- somehow, it may have been installed from an incompatible car (but cannot be for sue). I have the 20-way connector and the TCM itself and the wiring harness. I got several connectors from other G6 cars but the Engine harness that has the 49-way TCM connector is unique to the G6 GTP 3.9 2006. I could not find this car anywhere (not the MALIBU 3.9 2006 either). So, I plan to rewire a TCM connector I got from a 2010 IMPALA (which happen to use the same TCM but not the same engine harness and the needed connector).

Q: is this wise? Can it be done without damaging the connector?

if not, any advice as to how to proceed?
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Saturday, June 12th, 2021 AT 5:31 AM

10 Replies

Tiny
ASEMASTER6371
  • EXPERT
Good morning,

I attached the diagram for the 49 pin connector for you. The pins are numbered and the color wires need to go to the correct pin.

A lot of wires will be the same as the Impala but a lot will not be. Join the ones you connect by soldering and shrink-wrapping the wires for a good solid connection.

Once you replace the connector, see if the code is still there. If it is, let me know and we can continue on the diagnostic.

Roy
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Saturday, June 12th, 2021 AT 6:45 AM
Tiny
JAMESB2019
  • MEMBER
Sounds great.

I will get it done by end of day tomorrow. Please note the following and let me know if you disapprove:
1. TCM is from 2010 impala 3.5 flex fuel code 24252114.
2. TCM connector will be compatible after matching to 49-way connector diagram and instructions for the 3.9 G6 2006.
3. Transmission wiring harness along with its 20-way connector came from the same 2010 Impala 3.5 flex fuel code 24237264.

James
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Saturday, June 12th, 2021 AT 6:27 PM
Tiny
ASEMASTER6371
  • EXPERT
You need to use your TCM but using the connector from the 2010 Impala is okay. Make sure all the wires go to the correct pin number. That is the most important thing.

Roy
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Sunday, June 13th, 2021 AT 3:36 AM
Tiny
JAMESB2019
  • MEMBER
Hello Roy,

I ended up using 29-way connector from a 2006 GTP. All I had to do was splice the 49 and 20 way connectors. Here is an update:

This G6 GTP 3.9 Transmission FR3 4T65E version has been registering ISS 717 code for almost 2 years with no symptoms that the driver could detect. The ISS was replaced but that didn't erase the code. Recently, the TCM was replaced and programmed: Still no change. This past week, the 49-Way connector and wires to the TCM were replaced by splicing. The code 717 was registered again. Finally- 2 days ago, the 20-Way external connector and wires to the transmission¬ harness were replaced by splicing as well. When the job was done, everything was put back together¬ except the Electronic Brake Module Connector was left unplugged *by mistake* as the car was being tested. Later on, the connector to the EBM was reconnected while the car was running and the scanner connected to the DLC *again, I think the engine should've been turned off while¬ reconnecting the brake module.*¬ The scanner initially displayed a message: "Communication with the Body Control Module was Lost."¬ No code was registered. The car was taken for a drive cycle and the check engine light was actively cleared. Few minutes into the drive, the following occurred:

1. Code: 2534 Ignition switch/run low voltage
2. P0700 transmission
3. P0300 misfire
4. Check engine light blinking (not solid)
5. Acceleration began to suffer
6. Louder than normal noise¬

All spliced wires were rechecked for continuity.¬
What happened? The ignition wire (pink circuit 1339 or simply 39) from TCM 48-way connector pin 31 to transmission harness 20-way connector pin E showed no continuity. Is this normal when the key is in the off position? Does this wire go through a fuse or fusible link? The wiring diagram shows transmission fuse 4 in the junction block but no fusing in the wire in between pin 31 and pin E unless I am not reading the diagram correctly. All other connections showed continuity
I am not sure if I should test while the engine is running or while the key is in the on position or for that matter while battery voltage and ground are connected. Could this be a simple splicing issue or more? I think the misfire is the result of low voltage rather than damage to ignition switch.¬ ¬
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Monday, June 21st, 2021 AT 8:48 PM
Tiny
ASEMASTER6371
  • EXPERT
Since we are done with the connector, we are in a different area of an issue.

Site rules are 1 subject per question.

Please start a new question with all the most recent information and I will be glad to help.

Roy
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Tuesday, June 22nd, 2021 AT 2:03 AM
Tiny
JAMESB2019
  • MEMBER
Thanks for all your help, the splicing issues were corrected.

James
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Wednesday, July 7th, 2021 AT 9:49 AM
Tiny
ASEMASTER6371
  • EXPERT
You are welcome.

Always glad to help.

Roy
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Thursday, July 8th, 2021 AT 1:52 AM
Tiny
ERIC ANTHONY URIBE
  • MEMBER
I have the a question it is in relation to a previous post by member jamesb2019.

All spliced wires were rechecked for continuity.
What happened? The ignition wire (pink circuit 1339 or simply 39) from TCM 48-way connector pin 31 to transmission harness 20-way connector pin E showed no continuity. Is this normal when the key is in the off position? Does this wire go through a fuse or fusible link? The wiring diagram shows transmission fuse 4 in the junction block but no fusing in the wire in between pin 31 and pin E unless I am not reading the diagram correctly. All other connections showed continuity
I am not sure if I should test while the engine is running or while the key is in the on position or for that matter while battery voltage and ground are connected. Could this be a simple splicing issue or more? I think the misfire is the result of low voltage rather than damage to ignition switch.
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Tuesday, August 30th, 2022 AT 6:17 AM
Tiny
KEN L
  • ADMIN
This question is from last year so I don't know if the member will respond. Here is the transmission wiring diagrams and a guide to help you test the connections:

https://www.2carpros.com/articles/how-to-check-wiring

Check out the diagrams (below). Please let us know if you need anything else to get the problem fixed.

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Tuesday, August 30th, 2022 AT 1:18 PM
Tiny
JAMESB2019
  • MEMBER
Hello Ken, what is this member's question? I did two tests on each transmission wire (one by one): I did a continuity test, and I did voltage test wherever applicable. I then repaired, spliced new connectors and made sure all wires and harnesses were protected and channeled them through flex conduits. The pink wire was severed and was hanging by the thread which made the car misfire so badly (I do not recommend any attempt to drive the car if this wire is affected). It was very laborious to go through each and every wire (1000- dollar automotive electrical testing job if that was done at the dealership. I just happened to enjoy the electrical testing aspect of it. The rest was very tedious! It took way too long into the early morning hours by the time I was done, but it was worth it. And no, I do not recall any fusible links in this harness. There was a fusible link between the alternator and the battery through the starter. But that was when I was rewiring the car with new harnesses.
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Tuesday, August 30th, 2022 AT 7:26 PM

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