Electronic Throttle Module to PCM Communication?

TBODDEN

MEMBER
2003 CHEVROLET AVALANCHE
81,000 MILES

Having issues with Engine reduced power as soon as I start the truck up. The code is stating no communication between the throttle module and PCM.

I have changed the module on the driver side with a new and still having the same issues.

Wondering if anyone has an idea of what could be done?

Sunday, April 20th, 2025 AT 12:12 PM

4 Replies

KEN L

MASTER CERTIFIED MECHANIC
51,648 POSTS

Sure, I can help you but can I get the code number so we can go in the right direction? Most of the time when this happens it is because the accelerator position sensor goes bad, which is the throttle pedal itself. But you should check for power and ground at the module.

Here is a guide to help you:

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Power goes to the pink wire and the ground is the black wire, make sure the module is unplugged when testing. Let me know how it goes.

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Monday, April 21st, 2025 AT 11:54 AM

TBODDEN

MEMBER
3 POSTS

Thank you for the response, the code itself showing is P1518. I have attached an image below. I checked the fuse in the engine bay area fuse box all 2 of them which are 15 amp are working.

I hope this can help.

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Thursday, April 24th, 2025 AT 4:58 PM

KEN L

MASTER CERTIFIED MECHANIC
51,648 POSTS

After you changed the module out did you clear the codes? I have seen the accelerator position sensor go out and fool the throttle control module data which can cause this code.

P1518 - Throttle Actuator Control (TAC) Module Serial Data Circuit Malfunction

To be clear this is the part you changed out correct, also did you check the electrical connector for corrosion? I would also check the G104 ground for the module which is at the left rear of the engine. If everything looks okay, I would swap out the accelerator position sensor. Check out the images (below). Please let us know what happens.

Image (Click to make bigger)