Expedition 2WD V8-5.4L (2009)
Normal Operation
The Driver Seat Module (DSM) communicates with the scan tool through the Medium Speed Controller Area Network (MS-CAN). Circuits VDB06
(GY/OG) (MS-CAN +) and VDB07 (VT/OG) (MS-CAN -) provide the network connection to the DSM. Voltage for the DSM is provided by circuit
SBB45 (GY/RD). Circuit GD133 (BK) provides ground.
This pinpoint test is intended to diagnose the following:
-
Fuse
-
Wiring, terminals or connectors
-
DSM
PINPOINT TEST P: THE DSM DOES NOT RESPOND TO THE SCAN TOOL
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the
connector.
NOTE: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to Battery.
-------------------------------------------------
P1 CHECK THE DSM VOLTAGE SUPPLY CIRCUIT FOR AN OPEN
-
Ignition OFF.
-
Disconnect: DSM C341b.
-
Ignition ON.
-
Measure the voltage between the DSM C341b-1, circuit SBP02 (YE/RD), harness side and ground.
-
Is the voltage greater than 10 volts?
Yes
GO to P2.
No
VERIFY the SJB fuse 2 (15A) is OK. If OK, REPAIR the circuit. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit
short. CLEAR the DTCs. REPEAT the network test with the scan tool.
-------------------------------------------------
P2 CHECK THE DSM GROUND CIRCUIT FOR AN OPEN
-
Ignition OFF.
-
Disconnect: Negative Battery Cable.
-
Measure the resistance between the DSM C341b-24, circuit GD133 (BK), harness side and ground.
-
Is the resistance less than 5 ohms?
Yes
