When I tested CCM comms in the car, I unplugged the blue connector from the PCM to remove it from the bus, and then unplugged the ignition PASSkey connector to remove the resistor from the circuit. When I tried to turn the key to run, all I got were the $10 and $40 messages. No F0, so the CCM wasn't accepting my requests for instructions. I added the PCM back to the circuit, and all that did was add $41 messages to the bus. Still no F0. Only once I waited for the security timeout to complete and plugged the PASSkey harness back in did turning the key result in F0 polls being on the bus.
So yes, the documentation I have says that any request for PASSkey locations without the correct resistance value will return $00. But on my '95, I'm not sure how you're supposed to make that request when the CCM is just blasting out $10 and $40 polls and not making any $F0 requests for external devices.
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