Pinpoint Test F: THE DUAL AUTOMATIC TEMPERATURE CONTROL (DATC) MODULE DOES NOT RESPOND TO THE DIAGNOSTIC TOOL

WARNING: This page is about a different car, the 2005 Lincoln LS. However, it is still accessible from the selected car via links, so may be relevant.

F1 CHECK THE DATC MODULE C228A FOR DAMAGE
- Key in OFF position.
- Disconnect: DATC Module C228a.
- Inspect the DATC module C228a for damage.
- Is the DATC module C228a OK?
- Yes : GO to F2.
- No : REPAIR the DATC module C228a as necessary. TEST the system for normal operation.
F2 CHECK FOR AN OPEN BETWEEN THE DATA LINK CONNECTOR (DLC) C251 AND THE DATC MODULE C228A
- Measure the resistance between the DATC module C228a-12, circuit 4-FA10 (GY/BK), harness side and the DLC C251-2, circuit 4-EG7 (GY/RD), harness side.
  
  Fig 1: Measuring The Resistance Between The DATC Module C228a-12, Circuit 4-FA10 (GY/BK), Harness Side And The DLC C251-2, Circuit 4-EG7 (GY/RD)
  Courtesy of FORD MOTOR CO.
- Measure the resistance between the DATC module C228a-1, circuit 5-FA10 (BU/YE), harness side and the DLC C251-10, circuit 5-EG7 (BU/RD), harness side.
  
  Fig 2: Measuring The Resistance Between The DATC Module C228a-1, Circuit 5-FA10 (BU/YE), Harness Side And The DLC C251-10, Circuit 5-EG7 (BU/RD)
  Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?
- Yes : GO to F5.
- No : GO to F3.
F3 CHECK FOR AN OPEN BETWEEN THE DATC MODULE C228A AND JOINT CONNECTOR NO. 4 C223
- Disconnect: Joint Connector No. 4 C223.
- Measure the resistance between the DATC module C228a-12, circuit 4-FA10 (GY/BK), harness side and joint connector No. 4 C223-15, circuit 4-FA10 (GY/BK), harness side.
  
  Fig 3: Measuring The Resistance Between The DATC Module C228a-12, Circuit 4-FA10 (GY/BK), Harness Side And Joint Connector No. 4 C223-15, Circuit 4-FA10 (GY/BK)
  Courtesy of FORD MOTOR CO.
- Measure the resistance between the DATC module C228a-1, circuit 5-FA10 (BU/YE), harness side and joint connector No. 4 C223-8, circuit 5-FA10 (BU/YE), harness side.
  
  Fig 4: Measuring The Resistance Between The DATC Module C228a-1, Circuit 5-FA10 (BU/YE), Harness Side And Joint Connector No. 4 C223-8, Circuit 5-FA10 (BU/YE)
  Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?
- Yes : GO to F4.
- No : REPAIR the circuit in question. TEST the system for normal operation.
F4 CHECK JOINT CONNECTOR NO. 4 FOR AN OPEN
- Measure the resistance between joint connector No. 4 C223-14, component side and joint connector No. 4 C223-15, component side.
  
  Fig 5: Measuring The Resistance Between Joint Connector No. 4 C223-14, Component Side And Joint Connector No. 4 C223-15
  Courtesy of FORD MOTOR CO.
- Measure the resistance between joint connector No. 4 C223-8, component side and joint connector No. 4 C223-9, component side.
  
  Fig 6: Measuring The Resistance Between Joint Connector No. 4 C223-8, Component Side And Joint Connector No. 4 C223-9
  Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?
- Yes : REPAIR the circuit in question between the DLC C251 and joint connector No. 4 C223. CARRY OUT the diagnostic tool data link test.
- No : REPAIR joint connector No. 4 C223. TEST the system for normal operation.
F5 CHECK FOR CORRECT DATC MODULE OPERATION
- Disconnect all the DATC module connectors.
- Check for:
- corrosion
- push-out pins
- Connect all the DATC 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 DATC module. REFER to CONTROL COMPONENTS . TEST the system for normal operation.
  CARRY OUT the diagnostic tool data link test.
- 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 self-test.