Pinpoint Test L: DTC B2A20 - Vehicles With A Push Button Start System

NOTE: Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multi-meter probes.

L1 CHECK THE RFA MODULE FOR DTCs
- Connect the scan tool.
- Ignition OFF.
- Enter the following diagnostic mode on the scan tool: Self Test - RFA Module.
- Are any DTCs retrieved?
- Yes : CORRECT any RFA module DTCs before diagnosing DTC B2A20. REFER to the Master DTC Chart in MULTIFUNCTION ELECTRONIC MODULES .
- No : GO to L2.
L2 CHECK THE PCM START CIRCUIT FOR A SHORT TO VOLTAGE
- Disconnect: OTIS Diode.
- Disconnect: PCM C175B.
- Disconnect: Starter Relay.
- Measure the voltage between the OTIS diode, circuit CE336 (GN/WH), output side and ground.
  
  Fig 1: Measuring Voltage Between OTIS Diode Output Side, Circuit CE336 (GN/WH) And Ground
  Courtesy of FORD MOTOR CO.
- Is any voltage present?
- Yes : REPAIR circuit CE336 (GN/WH). CLEAR the DTC. REPEAT the self-test.
- No : GO to L3.
L3 CHECK FOR A SHORT TO VOLTAGE FROM THE PCM
- Connect: PCM C175B.
- Measure the voltage between the OTIS diode, circuit CE336 (GN/WH), output side and ground.
  
  Fig 2: Measuring Voltage Between OTIS Diode Output Side, Circuit CE336 (GN/WH) And Ground
  Courtesy of FORD MOTOR CO.
- Is any voltage present?
- Yes : INSTALL a new PCM. REFER to ELECTRONIC ENGINE CONTROLS . CLEAR the DTCs. REPEAT the self-test.
- No : GO to L4.
L4 CHECK FOR A SHORT TO VOLTAGE FROM THE STARTER RELAY
- Connect: Starter Relay.
- Measure the voltage between the OTIS diode, circuit CE336 (GN/WH), output side and ground.
  
  Fig 3: Measuring Voltage Between OTIS Diode Output Side, Circuit CE336 (GN/WH) And Ground
  Courtesy of FORD MOTOR CO.
- Is any voltage present?
- Yes : GO to L5.
- No : GO to L6.
L5 ISOLATE THE STARTER RELAY
- Disconnect: Starter Relay.
- Carry out the relay component test. Refer to OEM COMPONENT TESTING for component testing.
- Is the relay OK?
- Yes : GO to L6.
- No : INSTALL a new starter relay. CLEAR the DTCs. REPEAT the self-test.
L6 CHECK FOR CORRECT SJB OPERATION
- Disconnect all SJB connections.
- Check all SJB connections for:
  - corrosion.
  - pushed-out pins.
- spread terminals.
- Connect all SJB connections and make sure they are seated correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
- Yes : INSTALL a new SJB. REFER to MULTIFUNCTION ELECTRONIC MODULES . CLEAR the DTCs. TEST the system for normal operation.
- No : The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector.