Pinpoint Test F: No Communication With The Electronic Automatic Temperature Control (EATC) Module

F1 CHECK CIRCUIT GD116 (BK/VT) FOR AN OPEN
- Key in OFF position.
- Disconnect: DATC C2356a or EATC Module C228a.
- Measure the resistance between DATC C2356a-1 or EATC module C228a-1, circuit GD116 (BK/VT) and ground.
  
  Fig 1: Checking Circuit GD116 (BK/VT) For An Open
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
Yes : GO to F2.

No : REPAIR circuit GD116 (BK/VT). CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
F2 CHECK CIRCUITS SBP07 (WH/RD) AND CBP20 (YE/VT) FOR AN OPEN
- Key in ON position.
- Measure the voltage between DATC C2356a-26 or EATC module C228a-26, circuit SBP07 (WH/RD), DATC C2356a-19 or EATC module C228a-19, circuit CBP20 (YE/VT) and ground.
  
  Fig 2: Checking Circuits SBP07 (WH/RD) And CBP20 (YE/VT) For An Open
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
Yes : GO to MODULE COMMUNICATIONS NETWORK to diagnose the network concern.

No : VERIFY smart junction box (SJB) fuses 13 (7.5A) and 27 (7.5A) are OK. If OK, REPAIR circuit SBP07 (WH/RD) or CBP20 (YE/VT) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.