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Q: Green key light flashing, car wont start.

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My AC compressor would not accept coolant. My husband put a hot wire to the compressor to force it to take the coolant. Once he filled it, he plugged it back to the normal harness. The compressor kicked on one time and shut down the car. He started it again, but it immediately died, and now won't start back. There is a green key light flashing. The dealer said the PCM was bad, but another mechanic said there were protectors in place that could have blower before the PCM. Help....I don't want to buy a new PCM if I don't need to. Any suggestions???

My car has 70000 miles.

A: Hello, from what you describe it would appe...

Hello, from what you describe it would appear to me that you may be having an issue with your vehicle’s transponder and key.

The green key light that is flashing is actually not related to AC at all, it is in fact an anti-theft feature meant to protect the vehicle from being stolen. It is usually activated when the computer has detected any tampering with the electrical system, perhaps set off when you jumped the compressor to accept refrigerant.

As the transponder is built into the vehicle’s ignition switch where the key is inserted, it usually requires replacement with the key, and a very specific procedure in order to properly program the key to the vehicle. While this repair will probably not require a replacement PCM, it may require a new key and perhaps ignition switch.

I would recommend trying to manually lock and unlock the driver door, as well as inserting and powering up the vehicle. If these steps do not remedy the issue, I would then recommend having the vehicle serviced by a dealership for a proper diagnosis and any key recalibration/reprogramming that may necessary.

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