Pinpoint Test I: The Front Controls Interface Module (FCIM) Illumination Does Not Operate Correctly
Information and Entertainment System
Pinpoint Tests
Pinpoint Test I: The Front Controls Interface Module (FCIM) Illumination Does Not Operate Correctly
Normal Operation
The Front Controls Interface Module (FCIM) receives the illumination signal from the Smart Junction Box (SJB), and dims the illumination based on the position of the dimmer switch. The illumination signal is sent via the Medium Speed Controller Area Network (MS-CAN).
- DTC U0140 (Lost Communication With Body Control Module [GEM]) - sets when the FCIM is missing messages from the SJB for ignition state, illumination, or delayed accessory.
Because a missing ignition state or delayed accessory signal would cause multiple symptoms (since many modules would report this error), only the illumination signal is diagnosed in this pinpoint test.
In order for the FCIM to set DTC U0140, the illumination signal must be missing for greater than 5 seconds. In the event this signal is lost, the FCIM defaults to full nighttime brightness, resulting in a symptom of the FCIM being unable to dim.
This pinpoint test is intended to diagnose the following:
- Backlighting system concern
- FCIM
PINPOINT TEST I: THE FCIM ILLUMINATION DOES NOT OPERATE CORRECTLY
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I1 CHECK THE ILLUMINATION SIGNAL
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: FCIM DataLogger.
- Monitor the FCIM bezel illumination PID (ILL_FCIM) with the headlamp switch in the OFF position, and with the headlamp switch in the PARKING LAMPS position, while scrolling the dimmer switch from the lowest setting to the highest setting.
- Does the ILL_FCIM PID indicate "Max Daytime" with the headlamp switch off, and indicate an increasing number (1-19, Max Nighttime) as the dimmer switch is scrolled?
Yes
GO to I2.
No
REFER to Instrument Panel, Gauges and Warning Indicators to diagnose the backlighting system.
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I2 CHECK FOR CORRECT FCIM OPERATION
- Disconnect the FCIM connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the FCIM connector and make sure it seats correctly.
- Operate the system and determine if the concern is still present.
- Is the concern still present?
Yes
INSTALL a new FCIM. REFER to Front Controls Interface Module (FCIM) Front Controls Interface Module (FCIM). TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
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