Explorer AWD V8-4.6L (2010)
DTCs, refer to the Diagnostic Trouble Code (DTC) Chart in Body Control Systems. See: Body and Frame/Body Control Systems/Testing and
Inspection/Diagnostic Trouble Code Descriptions/Diagnostic Trouble Code (DTC) Chart
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If no DTCs related to the concern are retrieved, GO to Symptom Chart. See: Symptom Related Diagnostic Procedures
Principles Of Operation
Communications Network
Principles of Operation
Both the High Speed Controller Area Network (HS-CAN) and the Medium Speed Controller Area Network (MS-CAN) use an unshielded twisted-pair
cable of data (+) and data (-) circuits. The HS-CAN operates at a maximum data transfer speed of 500 Kbps and is designed for applications in which
modules must respond as rapidly as required by the driver or needed by the process being controlled. The MS-CAN operates at a maximum data transfer
speed of 125 Kbps for bus messages and is designed for general information transfer.
Controller Area Network (CAN) Fault Tolerance
NOTE: The oscilloscope traces below are taken from the Integrated Diagnostic System (IDS) oscilloscope using the IDS pre-configured CAN settings.
The traces are for both data (+) and data (-) taken simultaneously (2-channel) at a sample rate of 1 mega-sample per second (1MS/s) or greater.
Traces below are viewed at 500mV per division (vertical axis) and 20 microseconds (20µs) per division (horizontal axis). Readings taken with a
different oscilloscope vary from those shown. Compare any suspect readings to a known good vehicle.
Normal CAN Operation
The data (+) and data (-) circuits are each regulated to approximately 2.5 volts during neutral or rested network traffic. As messages are sent on the data
(+) circuit, voltage is increased by approximately 1.0 volt. Inversely, the data (-) circuit is reduced by approximately 1.0 volt when a message is sent.
Successful communication of a message can usually be identified by the slight spike at the end of a message transmission. Any signals that are
significantly different than the normal CAN waveform may cause network DTCs (U-codes) to set or may cause a complete network outage.
CAN Circuits Shorted Together