Pinpoint Test AU: DTC B2A20 Or U2472

NOTE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

AU1 RETRIEVE THE RECORDED DTCs FROM THE IC SELF-TEST
- Check for recorded IC DTCs from the self-test.
- Is DTC B2A20 recorded?
- Yes: GO to AU2 .
- No: For DTC U2472, GO to AU2 .
AU2 CHECK THE IC RUN/START VOLTAGE SUPPLY
- Ignition OFF.
- Disconnect: IC C220.
- Measure the voltage between the IC C220-20, circuit CBP29 (WH/VT), harness side and ground.
  
  Fig 1: Measuring Voltage Between IC C220-20, Circuit CBP29 (WH/VT), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Ignition ON.
- Measure the voltage between the IC C220-20, circuit CBP29 (WH/VT), harness side and ground.
  
  Fig 2: Measuring Voltage Between IC C220-20, Circuit CBP29 (WH/VT), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Place the key in the START position.
- Measure the voltage between the IC C220-20, circuit CBP29 (WH/VT), harness side and ground.
  
  Fig 3: Measuring Voltage Between IC C220-20, Circuit CBP29 (WH/VT), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage 0 volts in the OFF position and greater than 10 volts in the RUN and START positions?
- Yes: GO to AU3 .
- No: VERIFY the SJB fuse 29 (5A) is OK. If OK, REPAIR the circuit in question. If not OK, REFER to the SYSTEM WIRING DIAGRAMS article to identify the possible causes of the circuit short. TEST the system for normal operation.
AU3 CHECK THE SJB INPUT PIDs FROM THE IGNITION SWITCH
- Enter the following diagnostic mode on the scan tool: SJB DataLogger.
- Select the SJB ignition switch ACC (IGN_A_ECU), ignition switch OFF (IGN_O_ECU), ignition switch RUN (IGN_R_ECU), and ignition switch START (IGN_S_ECU) PIDs. Monitor the ignition switch PIDs while cycling the ignition switch from ACC, OFF, RUN and START.
- Do the SJB PIDs match the ignition switch position?
- Yes: GO to AU4 .
- No: REFER to STEERING COLUMN SWITCHES article to diagnose the ignition switch outputs to the SJB .
AU4 CHECK THE IC DTCs
- Enter the following diagnostic mode on the scan tool: IC Self-Test.
- Repeat the IC self-test. Clear the DTCs.
- Is DTC B2A20 or DTC U2472 still present?
- Yes: GO to AU5 .
- No: The system is operating correctly at this time. The DTC may have been set due to high network traffic.
AU5 CHECK FOR CORRECT SJB OPERATION
- Disconnect all the SJB connectors.
- Check for:
  - corrosion
  - damaged pins
  - pushed-out pins
- Connect all the SJB connectors and make sure they seat correctly.
- Operate the system and verify that the concern is still present.
- Is the concern still present?
- Yes: INSTALL a new SJB . REFER to MULTIFUNCTION ELECTRONIC MODULE article. TEST the system for normal operation.
  If the concern remains, REINSTALL the original SJB and GO to AU6 .
- No: The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
AU6 CHECK FOR CORRECT IC OPERATION
- Disconnect the IC connector.
- Check for:
  - corrosion
  - damaged pins
  - pushed-out pins
- Connect the IC connector and make sure it seats correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
- Yes: INSTALL a new IC . REFER to INSTRUMENT CLUSTER (IC) in this service information. 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.