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Old 12-17-2018, 08:01 PM   #1
bigmoe
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Ever pull a gas pedal wiring harness and TAC module?

My 5.3 LS engine donor was a low mileage '08 Tahoe. I bought the motor, wiring harness and gas pedal from an acquaintance who had it pulled and then decided to go with a 6.0 that came along. (he works in the auto insurance industry and sees all the good stuff that comes along) I got a gas pedal but he told me he never got the harness and TAC module. My local wrecker has an '08 truck. The other day I was there and didn't have much time but took a look. I followed the wire from the pedal up and left to WAY up under the dash. There was a short branch to the brake switch. I couldn't find where it came through the firewall when I looked under the hood nor could I see a little box. I've since been told the module is supposed to be behind the battery. I need to go out there and give it another try. Has anyone ever removed a gas pedal wiring harness from an '08? Should I grab the brake switch? Any idea where it comes through the firewall?
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Old 12-17-2018, 08:18 PM   #2
ls1nova71
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Re: Ever pull a gas pedal wiring harness and TAC module?

An '08 engine is a GenIV, they dont have TAC modules. Just get the pedal and as much of the wiring as possible and you will have to splice it into the engine harness.
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Old 12-17-2018, 08:48 PM   #3
bigmoe
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Re: Ever pull a gas pedal wiring harness and TAC module?

Quote:
Originally Posted by ls1nova71 View Post
An '08 engine is a GenIV, they dont have TAC modules. Just get the pedal and as much of the wiring as possible and you will have to splice it into the engine harness.
Really? Good to know. I might have been searching for a while, lol.

What about the brake switch? Does the PCM need a signal from the brake? I read somewhere there's a 12v feed from the pedal that is normally on, and off when the brake is applied - the opposite of a regular brake switch.
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Old 12-17-2018, 10:47 PM   #4
ls1nova71
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Re: Ever pull a gas pedal wiring harness and TAC module?

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Originally Posted by bigmoe View Post
What about the brake switch? Does the PCM need a signal from the brake? I read somewhere there's a 12v feed from the pedal that is normally on, and off when the brake is applied - the opposite of a regular brake switch.
The ECM does need a 12v signal from the brake switch, but only when the brakes are applied, so your existing switch should work. What you read about needing 12v with the brakes not applied is for the older GenIII engines.
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Old 12-17-2018, 11:01 PM   #5
bigmoe
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Re: Ever pull a gas pedal wiring harness and TAC module?

Thanks ls1! Some great info.
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