Pinpoint Test A: The Key-In-Ignition Chime Does Not Operate Correctly

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

A1 CHECK THE LCM - MONITOR THE LCM PID IGN_KEY
- Enter the following diagnostic mode on the diagnostic tool: LCM PID.
  Monitor the LCM PID IGN_KEY while placing the ignition key in and out of the ignition key cylinder.
- Does the LCM PID IGN_KEY value agree with the ignition switch positions?
- Yes : GO to A8.
- No : GO to A2.
A2 CHECK CIRCUIT 158 (BK/PK) FOR SHORT TO GROUND
- Key in OFF position.
- Disconnect: Key-in-Ignition Warning Switch.
- Disconnect: LCM C2145a.
- Measure the resistance between LCM C2145a pin 15, circuit 158 (BK/PK), and ground.
  
  Fig 1: Measuring Resistance Between LCM C2145a Pin 15, Circuit 158 (BK/PK), And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance greater than 10,000 ohms?
- Yes : GO to A3.
- No : REPAIR the circuit. TEST the system for normal operation.
A3 CHECK THE DRIVER DOOR OPEN WARNING INDICATOR SWITCH
- Open and close the driver door.
- Does the interior lighting illuminate with the door open and go out when the door is closed?
- Yes : GO to A4.
- No : Refer to INTERIOR LIGHTING .
A4 CHECK THE KEY-IN-IGNITION WARNING SWITCH - MONITOR THE LCM PID IGN KEY
- Key in OFF position.
- Connect the diagnostic tool.
- Key in ON position.
- Enter the following diagnostic mode on the diagnostic tool: LCM PID.
  NOTE: With the key-in-ignition, the LCM PID IGN_KEY should indicate IN. With the key-out of ignition, the LCM PID IGN_KEY should indicate OUT.
  
  Monitor the LCM PID IGN_KEY.
- Does the LCM PID IGN_KEY indicate IN and OUT correctly?
- Yes : All key-in-ignition inputs are OK. VERIFY other chimes operate. If they are inoperative, GO to A8.
- No : GO to A5.
A5 CHECK THE KEY-IN-IGNITION WARNING SWITCH KEY-IN-IGNITION SWITCH DISCONNECTED
- Key in OFF position.
- Disconnect: Key-In-Ignition Warning Switch.
- Key in ON position.
- Enter the following diagnostic mode on the diagnostic tool: LCM PID.
  Monitor the LCM PID IGN_KEY.
- Connect a 10A fused jumper wire between key-in-ignition warning switch connector, circuit 158 (BK/PK), and ground.
  
  Fig 2: Connecting 10A Fused Jumper Wire Between Key-In-Ignition Warning Switch Connector, Circuit 158 (BK/PK) And Ground
  Courtesy of FORD MOTOR CO.
- Does the LCM PID IGN_KEY indicate IN with the jumper wire connected and OUT with the jumper wire disconnected?
- Yes : INSTALL a new key-in-ignition warning switch. REFER to SWITCH - KEY-IN-IGNITION WARNING . CLEAR the DTCs. TEST the system for normal operation.
- No : GO to A6.
A6 CHECK CIRCUIT 158 (BK/PK) FOR OPEN
- Key in OFF position.
- Disconnect: LCM C2145a.
- Measure the resistance between LCM C2145a pin 15, circuit 158 (BK/PK), harness side and the key-in-ignition warning switch circuit 158 (BK/PK) harness side.
  
  Fig 3: Measuring Resistance Between LCM C2145a Pin 15 And Key-In-Ignition Warning Switch Circuit 158 (BK/PK)
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
- Yes : GO to A7.
- No : REPAIR the circuit. TEST the system for normal operation.
A7 CHECK CIRCUIT 158 (BK/PK) FOR SHORT TO GROUND
- Measure the resistance between LCM C2145a pin 15, circuit 158 (BK/PK), harness side and ground.
  
  Fig 4: Measuring Resistance Between LCM C2145a Pin 15, Circuit 158 (BK/PK), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance greater than 10,000 ohms?
- Yes : GO to A8.
- No : REPAIR the circuit. CLEAR the DTCs. TEST the system for normal operation.
A8 CHECK FOR CORRECT MODULE OPERATION
- Disconnect all connectors.
- Check:
  - for corrosion
  - for push-out pins
  - connector seated correctly
- Connect all 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 LCM. Refer to MULTIFUNCTION ELECTRONIC MODULES . REPEAT the LCM self-test.
- No : The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.