Pinpoint Test K: The Fire Suppression Module (FSM) Does Not Respond To The Diagnostic Tool

WARNING: This page is about a different car, the 2006 Mercury Grand Marquis and 2006 Ford Crown Victoria. However, it is still accessible from the selected car via links, so may be relevant.

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

K1 CHECK THE FSM C3281A FOR DAMAGE
- Key in OFF position.
- Disconnect the battery. Refer to BATTERY, MOUNTING AND CABLES .
- Disconnect: FSM C3281a.
- Inspect the FSM C3281a for damage.
- Is the FSM C3281a OK?
Yes : GO to K2.

No : REPAIR the FSM C3281a as necessary. CONNECT the FSM C3281a. CONNECT the battery. REFER to BATTERY, MOUNTING AND CABLES . CARRY OUT the diagnostic tool data link test.
K2 CHECK THE CAN CIRCUITS BETWEEN THE DLC AND THE FSM FOR AN OPEN
- Measure the resistance between the FSM C3281a-16, circuit 1827 (WH/LG), harness side and the DLC C251-6, circuit 1827 (WH/LG), harness side.
  
  Fig 1: Checking The CAN Circuits Between The DLC And The FSM For An Open (1 Of 2)
  Courtesy of FORD MOTOR CO.
- Measure the resistance between the FSM C3281a-8, circuit 1828 (PK/LG), harness side and the DLC C251-14, circuit 1828 (PK/LG), harness side.
  
  Fig 2: Checking The CAN Circuits Between The DLC And The FSM For An Open (2 Of 2)
  Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?
Yes : GO to K3.

No : REPAIR the circuit. CONNECT the FSM C3281a. CONNECT the battery. REFER to BATTERY, MOUNTING AND CABLES . CARRY OUT the diagnostic tool data link test.
K3 CHECK THE ISO 9141 CIRCUIT BETWEEN THE DLC AND THE FSM FOR AN OPEN
- Measure the resistance between the FSM C3281a-9, circuit 70 (LB/WH), harness side and the DLC C251-7, circuit 70 (LB/WH), harness side.
  
  Fig 3: Checking The ISO 9141 Circuit Between The DLC And The FSM For An Open
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
Yes : GO to K4.

No : REPAIR the circuit. CONNECT the FSM C3281a. CONNECT the battery. REFER to BATTERY, MOUNTING AND CABLES . CARRY OUT the diagnostic tool data link test.
K4 CHECK FOR CORRECT FSM OPERATION
- Disconnect all the FSM connectors.
- Check for:
  - corrosion
  - pushed-out pins
- Connect all the FSM connectors and make sure they seat correctly.
- Connect the battery. Refer to BATTERY, MOUNTING AND CABLES .
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes : INSTALL a new FSM. REFER to FIRE SUPPRESSION SYSTEM . CLEAR the DTCs. REPEAT the self-test. 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.