Car is intermittently going in limp mode?

2006 PONTIAC G6
350,000 MILES • AUTOMATIC
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CHAT1978
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This happens while driving or sometimes at the first start. Door locks acting erratically, error displays on the odometer, speedometer goes to zero, temperature gauge doesn’t register and the car shifts to a lower gear and stays there until the odometer starts working again
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May 25, 2026 at 2:23 AM
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STRAILER
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This sounds like you have a bad instrument cluster, but we need to scan the CAN system this video will show you how. Also it can be a bad ground for the IPC/BCM but the codes would be the first check. Here is the location of the BCM grounds g305 and g203, also I would remove the electrical connectors at the BCM and IPC to look for corrosion. Here is the location of the BCM, disconnect the battery first. Check out the images (below). Please let me know what happens.
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May 26, 2026 at 2:25 AM
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