Pinpoint Test K: The ACM Does Not Respond To The Scan Tool

WARNING: This page is about a different car, the 2010 Lincoln MKX and 2010 Ford Edge. 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 .

K1 CHECK THE ACM VOLTAGE SUPPLY CIRCUITS FOR AN OPEN
- Ignition OFF.
- Disconnect: ACM C240a.
- Ignition ON.
- Measure the voltage between the ACM C240a-1, circuit SBP39 (WH/RD), harness side and ground; and between the ACM C240a-2, circuit CBP41 (BU) (without navigation), harness side and ground.
  
  Fig 1: Measuring Voltage Between ACM C240a-1, Circuit SBP39 (WH/RD) And Ground
  Courtesy of FORD MOTOR CO.
- Are the voltages greater than 10 volts?
- Yes: GO to K2 .
- No: VERIFY the Smart Junction Box (SJB) fuse 39 (20A) or fuse 41 (15A) (without navigation) is OK. If OK, REPAIR the circuit in question. If not OK, REFER to the SYSTEM WIRING DIAGRAMS for Edge or SYSTEM WIRING DIAGRAMS for MKX to identify the possible causes of the circuit short. CLEAR the DTCs. REPEAT the network test with the scan tool.
K2 CHECK THE ACM GROUND CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: Negative Battery Cable.
- Measure the resistance between the ACM C240a-13, circuit GD114 (BK/BU), harness side and ground.
  
  Fig 2: Measuring Resistance Between ACM C240a-13, Circuit GD114 (BK/BU) And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
- Yes: GO to K3 .
- No: REPAIR the circuit. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.
K3 CHECK THE MS-CAN CIRCUITS BETWEEN THE ACM AND THE DLC FOR AN OPEN
- Disconnect: ACM C240b.
- Measure the resistance between the ACM C240b-15, circuit VDB06 (GY/OG), harness side and the DLC C251-3, circuit VDB06 (GY/OG), harness side.
  
  Fig 3: Measuring Resistance Between ACM C240b-15, Circuit VDB06 (GY/OG) And DLC C251-3, Circuit VDB06 (GY/OG)
  Courtesy of FORD MOTOR CO.
- Measure the resistance between the ACM C240b-16, circuit VDB07 (VT/OG), harness side and the DLC C251-11, circuit VDB07 (VT/OG), harness side.
  
  Fig 4: Measuring Resistance Between ACM C240b-16, Circuit VDB07 (VT/OG) And DLC C251-11, Circuit VDB07 (VT/OG)
  Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?
- Yes: CONNECT the negative battery cable. GO to K4 .
- No: REPAIR the circuit in question. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.
K4 CHECK FOR CORRECT ACM OPERATION
- Disconnect all the ACM connectors.
- Check for:
  - corrosion
  - damaged pins
  - pushed-out pins
- Connect all the ACM connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
- Yes: INSTALL a new ACM . REFER to INFORMATION AND ENTERTAINMENT SYSTEMS . CLEAR the DTCs. REPEAT the network test with the scan tool. TEST the system for normal operation.
- 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.