CCD Bus

The CCD Bus is a 2 wire communication port in which controllers and modules exchange information. PCM transmits monitored input information and control requests to other modules on CCD Bus. PCM also receives information and requests from other controllers that will effect the control of its outputs. The CCD Bus has a measurable voltage of about 2.5 volts.

The following items transmit or receive information from PCM through the CCD Bus:

1. Air Conditioning Switch
   
   Transmits A/C select command inputs to PCM.
2. Air Conditioning Evaporator Temperature Sensor
   
   Transmits evaporator temperature input to PCM.
3. Transaxle Range (TR) Sensor
   
   Transmits transaxle gear position to PCM.
4. Speed (Cruise) Control Switch
   
   Transmits speed control engage command inputs to PCM.
5. Malfunction Indicator Light (MIL)
   
   Receives On/Off command from PCM.
6. Engine RPM (Tachometer)
   
   Receives engine RPM signal from PCM.

The following components access or send information on the CCD Bus:

• Instrument Panel (I/P).
• Body Control Module (BCM).
• Air Bag System Diagnostic Module (ABSDM).
• Full Automatic Temperature Control (ATC) display head.
• Controller Anti-lock Brake (CAB).
• Transmission Control Module (TCM).
• Powertrain Control Module (PCM).
• Traveler module (if equipped).