Pinpoint Test I: The Defrost System Will Not Shut Off Automatically

I1 CHECK FOR A SHORT TO POWER
- Key in OFF position.
- Disconnect: Heated Rear Window Relay.
- Key in START position.
- With the engine running, measure the voltage between the heated rear window relay C2021 pin 87, CJB side and ground.
  
  Fig 1: Measuring Voltage Between Heated Rear Window Relay C2021 Pin 87, CJB Side And Ground
  Courtesy of FORD MOTOR CO.
- Is any voltage present?
  - Yes : Go to I2.
  - No : Go to I4.
I2 CHECK CIRCUIT 15S-HB19 (GN/BU)
- Key in OFF position.
- Disconnect: CJB C270a.
- Key in START position.
- With the engine running, measure the voltage between the heated rear window relay C2021 pin 87, CJB side and ground.
  
  Fig 2: Measuring Voltage Between Heated Rear Window Relay C2021 Pin 87, CJB Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
  - Yes : Go to I3.
  - No : REPAIR the circuit. TEST the system for normal operation.
I3 CHECK CIRCUIT 15S-HB2 (GN/BU)
- Key in OFF position.
- Disconnect: CJB C270d.
- Key in START position.
- With the CJB C270a still disconnected and the engine running, measure the voltage between the heated rear window relay C2021 pin 87, CJB side and ground.
  
  Fig 3: Measuring Voltage Between Heated Rear Window Relay C2021 Pin 87, CJB Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
  - Yes : INSTALL a new CJB. TEST the system for normal operation.
  - No : REPAIR the circuit. TEST the system for normal operation.
I4 CHECK THE HEATED REAR WINDOW RELAY COIL GROUND CIRCUIT
- Key in OFF position.
- Disconnect: Heater Control Module C2263.
- Key in START position.
- With the engine running, measure the resistance between the heated rear window relay C2021 pin 85, CJB side and ground.
  
  Fig 4: Measuring Resistance Between Relay Connector And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance greater than 10,000 ohms?
  - Yes : Go to I5.
  - No : Go to I6.
I5 CHECK THE HEATER CONTROL MODULE OPERATION
- Disconnect all heater control module connectors.
- Check for:
  - Corrosion
  - Pushed-out pins
- Connect all heater control module 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 heater control module. Refer to CONTROL COMPONENTS . TEST the system for normal operation.
  - No : The system is working correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.
I6 CHECK THE GENERIC ELECTRONIC MODULE (GEM) INTEGRITY
- Key in OFF position.
- Disconnect: GEM C201e.
- Measure the resistance between the heated rear window relay C2021 pin 85, CJB side and ground.
  
  Fig 5: Measuring Resistance Between Relay Connector And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance greater than 10,000 ohms?
  - Yes : Go to I7.
  - No : REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
I7 CHECK FOR CORRECT GEM OPERATION
- Disconnect all GEM connectors.
- Check for:
  - Corrosion
  - Pushed-out pins
- Connect all GEM 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 GEM. Refer to MULTIFUNCTION ELECTRONIC MODULES . TEST the system for normal operation.
  - No : The system is operating correctly at this time. The concern may have caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.