Pinpoint Test O: The Driver Seat Module (DSM) Does Not Respond To The Scan Tool

Refer to appropriate SYSTEM WIRING DIAGRAMS article, Module Communications Network for schematic and connector information.

Refer to appropriate SYSTEM WIRING DIAGRAMS article, Memory Seats for schematic and connector information.

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. The DSM shares the MS-CAN with the instrument cluster (IC), the accessory protocol interface module (APIM), the smart junction box (SJB), the HVAC module (if equipped), the audio control module (ACM), the audio digital signal processing (DSP) module (if equipped), the satellite digital audio receiver system (SDARS) module (if equipped), the parking aid module (PAM) (if equipped), the liftgate/trunk module (LTM) (if equipped), the rear entertainment module (RETM) (if equipped) and the dual climate control seat module (DCSM) (if equipped). Voltage for the DSM is provided by circuits SBP12 (GN/RD) and SBB60 (GN/RD). Circuits GD133 (BK) and GD145 (BK/BU) provide ground.

This pinpoint test is intended to diagnose the following:

• Fuse
• Wiring, terminals or connectors
• DSM

PINPOINT TEST O: THE DRIVER SEAT MODULE (DSM) DOES NOT RESPOND TO THE SCAN TOOL 

1. O1 CHECK THE DSM VOLTAGE SUPPLY CIRCUITS FOR AN OPEN 
   • Key in OFF position.
   • Disconnect: DSM C3299a
   • Disconnect: DSM C3299b
   Fig 1: Checking Circuit For Voltage
   Courtesy of FORD MOTOR CO.
   • Measure the voltage between the DSM C3299a-1, circuit SBB60 (GN/RD), harness side and ground.
   Fig 2: Measuring Voltage
   Courtesy of FORD MOTOR CO.
   • Measure the voltage between the DSM C3299b-1, circuit SBP12 (GN/RD), harness side and ground.
   • Are the voltages greater than 10 volts? 
   1. YES  : Go to  O2.
   2. NO  : VERIFY the battery junction box (BJB) fuse 60 (30A) or the SJB fuse 12 (7.5) are OK. If OK, REPAIR the circuit in question. CLEAR the DTCs. REPEAT the network test with the scan tool.
2. O2 CHECK THE DSM GROUND CIRCUIT FOR AN OPEN 
   Fig 3: Checking Circuit For Open
   Courtesy of FORD MOTOR CO.
   • Measure the resistance between the DSM C3299a-2, circuit GD145 (BK/BU), harness side and ground.
   Fig 4: Measuring Resistance
   Courtesy of FORD MOTOR CO.
   • Measure the resistance between the DSM C3299b-24, circuit GD133 (BK), harness side and ground.
   • Are the resistances less than 5 ohms? 
   1. YES  : Go to  O3.
   2. NO  : REPAIR the circuit in question. CLEAR the DTCs. REPEAT the network test with the scan tool.
3. O3 CHECK THE MS-CAN CIRCUITS BETWEEN THE DATA LINK CONNECTOR (DLC) AND THE DSM FOR AN OPEN 
   • Key in OFF position.
   • Disconnect: DSM C3299d
   Fig 5: Measuring Resistance
   Courtesy of FORD MOTOR CO.
   • Measure the resistance between the DSM C3299d-10, circuit VDB06 (GY/OG), harness side and the DLC C251-3, circuit VDB06 (GY/OG), harness side.
   Fig 6: Measuring Resistance
   Courtesy of FORD MOTOR CO.
   • Measure the resistance between the DSM C3299d-9, circuit VDB07 (VT/OG), harness side and the DLC C251-11, circuit VDB07 (VT/OG), harness side.
   • Are the resistances less than 5 ohms? 
   1. YES  : Go to  O4.
   2. NO  : REPAIR the circuit in question. CLEAR the DTCs. REPEAT the network test with the scan tool.
4. O4 CHECK FOR CORRECT DSM OPERATION 
   • Disconnect all the DSM connectors.
   • Check for:
     • corrosion
     • damaged pins
     • pushed-out pins
   • Connect all the DSM connectors and make sure they seat correctly.
   • Operate the system and verify the concern is still present.
   • Is the concern still present? 
   1. YES  : INSTALL a new DSM. REFER to MULTIFUNCTION ELECTRONIC MODULES article. REPEAT the network test with the scan tool.
   2. NO  : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the network test with the scan tool.