Expedition 2WD V8-5.4L (2009)
Responding During Network Test
Normal Operation
The Medium Speed Controller Area Network (MS-CAN) uses an unshielded twisted pair cable. Circuits VDB06 (GY/OG) and VDB07 (VT/OG)
provide the network connection to all modules on the network.
In the event that one of the 2 network circuits (MS-CAN + or MS-CAN -) becomes open to a module on the network, unreliable network communication
to all modules on the network may result.
This pinpoint test is intended to diagnose the following:
-
Wiring, terminals or connectors
PINPOINT TEST U: INTERMITTENT NO MS-CAN COMMUNICATION, ONE OR MORE MODULES ARE NOT RESPONDING
DURING NETWORK TEST
NOTE: Most faults are due to connector and/or wiring concerns. Carry out a thorough inspection and verification before proceeding with the Pinpoint
Test. See: Initial Inspection and Diagnostic Overview/Communications Network/Inspection And Verification
NOTE: Various network DTCs will set while disabling modules in this test procedure which will need to be cleared after the diagnostic procedure is
completed.
NOTE: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to Battery.
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U1 CHECK THE DLC PINS FOR DAMAGE
-
Ignition OFF.
-
Disconnect the scan tool cable from the Data Link Connector (DLC).
-
Inspect DLC pins 3 and 11 for damage.
-
Are DLC pins 3 and 11 OK?
Yes
GO to U2.
No
REPAIR the DLC as necessary. CLEAR the DTCs. REPEAT the network test with the scan tool.
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U2 CHECK THE MS-CAN TERMINATION RESISTANCE
-
Disconnect: Negative Battery Cable.
-
Measure the resistance between the DLC C251-3, circuit VDB06 (GY/OG), harness side and the DLC C251-11, circuit VDB07 (VT/OG), harness
side.
-
Is the resistance between 54 and 66 ohms?
Yes
GO to U3.
