Cannot connect to PCM with scanner?
Thread Starter
Drifting
Joined: Jul 2001
Posts: 1,296
Likes: 0
From: Largo Florida
Cannot connect to PCM with scanner?
I use Autotap to scan the car. Every once in a while the software would have trouble reading the COM port. Now it cannot connect at all. Howerver, I can connect to another car. I have tried with just the ignition on and the car running. I have tried 2 different PCMs and still no luck. I even took apart the under the dash connector to make the female connector fix tighter. Still no connection. Anyone seen this one before?
Burning Brakes
Joined: Oct 2002
Posts: 1,152
Likes: 1
From: Wichita KS
Re: Cannot connect to PCM with scanner? (ericcer)
I don't use Autotap, but my Datamaster program has trouble establishing communication with the PCM once in a while..Here is a direct quote from my Datamaster manual...
Note to Corvette Owners
Corvettes require a special data protocol when connecting with Datamaster due to the Central Control Module (CCM), which updates the dashboard and Heating/Ventilation (HVAC) systems. If the CCM is not working correctly, or the vehicle has been modified to remove these components, it may be necessary to select the Options-Advanced-Disable ALDL Handshake and/or the Options-Advanced-Disable Dash Refresh in order to communicate and receive data. When first connecting, it will not be uncommon to receive multiple errors until a clear communication path has been established. If the Dash Refresh is disabled, the dashboard will be frozen until data collection is stopped. This will result in the Service ASR light turning on until the vehicle ignition is cycled "OFF". Also, during very long data collection periods, it is possible that the Service ASR light may be set. The light will be reset after cycling the vehicle ignition "OFF".
I would assume Autotap has the same issue since it is specific to the late Corvettes...
Note to Corvette Owners
Corvettes require a special data protocol when connecting with Datamaster due to the Central Control Module (CCM), which updates the dashboard and Heating/Ventilation (HVAC) systems. If the CCM is not working correctly, or the vehicle has been modified to remove these components, it may be necessary to select the Options-Advanced-Disable ALDL Handshake and/or the Options-Advanced-Disable Dash Refresh in order to communicate and receive data. When first connecting, it will not be uncommon to receive multiple errors until a clear communication path has been established. If the Dash Refresh is disabled, the dashboard will be frozen until data collection is stopped. This will result in the Service ASR light turning on until the vehicle ignition is cycled "OFF". Also, during very long data collection periods, it is possible that the Service ASR light may be set. The light will be reset after cycling the vehicle ignition "OFF".
I would assume Autotap has the same issue since it is specific to the late Corvettes...
