Pinpoint Test F: The Instrument Panel Illumination Does Not Dim

Refer to appropriate SYSTEM WIRING DIAGRAMS article, Cluster and Panel Illumination for schematic and connector information.

Normal Operation 

The lighting control module (LCM) supplies a variable pulse-width modulated (PWM) voltage to the instrument panel switches through circuit 484 (OG/BK). The LCM uses the instrument panel dimmer switch to determine the intensity of switch illumination.

• DTC B2212 (Panel Dim Switch Out Of Range) - is an on-demand DTC that sets when the LCM detects an out of range condition on the dimmer switch input circuit.

This pinpoint test is intended to diagnose the following:

• Wiring, terminals or connectors
• Instrument panel dimmer switch
• LCM

PINPOINT TEST F: THE INSTRUMENT PANEL ILLUMINATION DOES NOT DIM 

1. F1 CHECK THE DTCs FROM THE LCM SELF-TEST 
   • Check the recorded results from the LCM self-test.
   • Is DTC B2212 recorded? 
   1. YES  : Go to  F2.
   2. NO  : Go to  F6.
2. F2 CHECK CIRCUIT 1036 (BN/WH) FOR A SHORT TO VOLTAGE 
   • Key in OFF position.
   • Disconnect: LCM C2145a
   • Key in ON position.
   Fig 1: Checking Circuit For A Short To Voltage
   Courtesy of FORD MOTOR CO.
   • Measure the voltage between the LCM C2145a-7, circuit 1036 (BN/WH), harness side and ground.
   • Is any voltage present? 
   1. YES  : REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
   2. NO  : Go to  F3.
3. F3 CHECK CIRCUIT 1036 (BN/WH) FOR AN OPEN OR SHORT TO GROUND 
   • Key in OFF position.
   • Disconnect: Instrument Panel Dimmer Switch C205b
   Fig 2: Checking Circuit For An Open Or Short To Ground
   Courtesy of FORD MOTOR CO.
   • Measure the resistance between the LCM C2145a-7, circuit 1036 (BN/WH), harness side and the instrument panel dimmer switch C205b-6, circuit 1036 (BN/WH), harness side; and between the LCM C2145a-7, circuit 1036 (BN/WH), harness side and ground.
   • Is the resistance less than 5 ohms between the LCM and the instrument panel dimmer switch, and greater than 10,000 ohms between the LCM and ground? 
   1. YES  : Go to  F4.
   2. NO  : REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
4. F4 CHECK CIRCUIT 57 (BK) FOR AN OPEN 
   Fig 3: Checking Circuit For Open
   Courtesy of FORD MOTOR CO.
   • Measure the resistance between the instrument panel dimmer switch C205b-4, circuit 57 (BK), harness side and ground.
   • Is the resistance less than 5 ohms? 
   1. YES  : Go to  F5.
   2. NO  : REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
5. F5 CHECK THE INSTRUMENT PANEL DIMMER SWITCH 
   • Carry out the component tests for the instrument panel dimmer switch. Refer to COMPONENT TESTING article.
   • Does the instrument panel dimmer switch pass the component tests? 
   1. YES  : Go to  F7.
   2. NO  : INSTALL a new instrument panel dimmer switch. REFER to Instrument Panel Dimmer Switch . CLEAR the DTCs. REPEAT the self-test.
6. F6 CHECK CIRCUIT 484 (OG/BK) FOR SHORT TO VOLTAGE 
   • Key in OFF position.
   • Disconnect: LCM C2145c
   • Key in ON position.
   Fig 4: Checking Circuit For Short To Voltage
   Courtesy of FORD MOTOR CO.
   • Measure the voltage between the LCM C2145c-3, circuit 484 (OG/BK), harness side and ground.
   • Is any voltage present? 
   1. YES  : REPAIR the circuit. TEST the system for normal operation.
   2. NO  : Go to  F7.
7. F7 CHECK FOR CORRECT LCM OPERATION 
   • Key in OFF position.
   • Disconnect all the LCM connectors.
   • Check for:
     • corrosion
     • damaged pins
     • pushed-out pins
   • Connect all the LCM connectors and make sure they seat correctly.
   • Operate the system and verify the concern is still present.
   • Is the concern is still present? 
   1. YES  : INSTALL a new LCM. REFER to MULTIFUNCTION ELECTRONIC MODULES article. TEST the system for normal operation.
   2. 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.