Pinpoint Test I: The DSM Does Not Respond To The Scan Tool

WARNING: This page is about a different car, the 2013 Ford F-550 Super Duty, 2013 Ford F-450 Super Duty, 2013 Ford F-350 Super Duty, and 2013 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: 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, MOUNTING AND CABLES .

I1 CHECK THE DSM VOLTAGE SUPPLY CIRCUITS FOR AN OPEN
- Ignition OFF.
- Disconnect: DSM C341A and DSM C341B.
- Measure the voltage between the DSM C341A-1, circuit CBX05 (VT/RD), harness side and ground.
  
  Fig 1: Measuring Voltage Between DSM C341A-1, Circuit CBX05 (VT/RD) And Ground
  Courtesy of FORD MOTOR CO.
- Measure the voltage between the DSM C341B-1, circuit CBX03 (BU/RD), harness side and ground.
  
  Fig 2: Measuring Voltage Between DSM C341B-1, Circuit CBX03 (BU/RD) And Ground
  Courtesy of FORD MOTOR CO.
- Are the voltages greater than 10 volts?
1. Yes : GO to I2.
2. No : VERIFY the Battery Junction Box (BJB) fuse 9 (30A) or the Body Control Module (BCM) fuse 6 (5A) is OK. If OK, REPAIR the circuit in question. If not OK, REFER to the OEM ELECTRICAL WIRING DIAGRAM INTRODUCTION to identify the possible causes of the circuit short. CLEAR the DTCs. REPEAT the network test with the scan tool.
I2 CHECK THE DSM GROUND CIRCUITS FOR AN OPEN
- Ignition OFF.
- Disconnect: Negative Battery Cable.
- Measure the resistance between the DSM C341A-2, circuit GD906 (BK/GY), harness side and ground.
  
  Fig 3: Measuring Resistance Between DSM C341A-2, Circuit GD906 (BK/GY)
  Courtesy of FORD MOTOR CO.
- Measure the resistance between the DSM C341B-24, circuit GD905 (BK/GN), harness side and ground.
  
  Fig 4: Measuring Resistance Between DSM C341B-24, Circuit GD905 (BK/GN) And Ground
  Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?
1. Yes : GO to I3.
2. No : REPAIR the circuit in question. CLEAR the DTCs. REPEAT the network test with the scan tool.
I3 CHECK THE MS-CAN CIRCUITS BETWEEN THE DSM AND THE DLC FOR AN OPEN
- Ignition OFF.
- Disconnect: DSM C341D.
- Measure the resistance between the DSM C341D-10, circuit VDB06 (GY/OG), harness side and the DLC C251-3, circuit VDB06 (GY/OG), harness side.
  
  Fig 5: Measuring Resistance Between DSM C341D-10, Circuit VDB06 (GY/OG) And DLC C251-3, Circuit VDB06 (GY/OG)
  Courtesy of FORD MOTOR CO.
- Measure the resistance between the DSM C341D-9, circuit VDB07 (VT/OG), harness side and the DLC C251-11, circuit VDB07 (VT/OG), harness side.
  
  Fig 6: Measuring Resistance Between DSM C341D-9, Circuit VDB07 (VT/OG) And DLC C251-11, Circuit VDB07 (VT/OG)
  Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?
1. Yes : CONNECT the negative battery cable. GO to I4.
2. No : REPAIR the circuit in question. CLEAR the DTCs. REPEAT the network test with the scan tool.
I4 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 SEATING . CLEAR the DTCs. REPEAT the network test with the scan tool. TEST the system for normal operation.
2. No : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.