Code U0100, problems with ikey?

RAYMOND GREEN

MEMBER
2013 NISSAN ALTIMA
180,000 MILES

I bought a keyless entry module that came with the key fob and the ECM, but it still won't do anything. The dash just says I key issues read owner's manual or something.

Monday, March 18th, 2024 AT 11:01 AM

4 Replies

KEN L

MASTER CERTIFIED MECHANIC
47,643 POSTS

The aftermarket keyless entry module will probably not work with this car so that gives you the U0100 code which indicates a communication problem with the Engine Control Module (ECM). Specifically, this code means "Lost Communication With ECM/PCM 'A'." Can you tell me how you installed the unit? Also, can you disconnect the aftermarket part and is the car okay?

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Monday, March 18th, 2024 AT 1:12 PM

RAYMOND GREEN

MEMBER
15 POSTS

Well, the reason I bought it was because of this problem, so no it's still doing the same thing except with this new one in it won't do anything. The acc for the radio don't work or anything.

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Monday, March 18th, 2024 AT 3:59 PM

KEN L

MASTER CERTIFIED MECHANIC
47,643 POSTS

Gotcha, okay when the keyless module goes out or you have lost power to the grn/yel wire at the push button start module. Here is a guide to help check it for you and I have included the push button wiring diagrams so you can see how the system works.

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

Check out the images (below). Please let us know what happens.

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