Where is the TCM located?

Tiny
BOBBY7789
  • MEMBER
  • 2005 PONTIAC GRAND PRIX
  • 3.8L
  • V6
  • 2WD
  • AUTOMATIC
  • 260,000 MILES
I'm needing to replace the TCM in my car listed above GT, but can't find where it's located?
Sunday, April 7th, 2024 AT 3:15 PM

3 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

This vehicle doesn't have a separate module for the transmission (TCM). Instead, the transmission is controlled by the powertrain control module (PCM). It is located at the front left (driver's side) of the engine compartment.

I attached the wiring schematic below, so you have a reference.

Let me know if this helps or if you have other questions.

Take care,

joe

See pics below. Note: I had to cut the schematic in half to make it readable. I did overlap the two so you can follow from one to the next.
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Sunday, April 7th, 2024 AT 7:04 PM
Tiny
TURBOJAY
  • MEMBER
  • 2 POSTS
Don't show the location of TCM?
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Friday, June 13th, 2025 AT 11:53 AM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
There is only the PCM that controls the transmission. The PCM is under the dash on the left side near the data port connector. Check out the images (below). Let us know if you need anything else.
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Friday, June 13th, 2025 AT 11:57 AM

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