Pinpoint Test B: The Instrument Cluster (IC) Illumination Is Inoperative

Normal Operation 

The lighting control module (LCM) communicates the requested level of backlighting intensity to the instrument cluster (IC) through the standard corporate protocol (SCP) network.

This pinpoint test is intended to diagnose the following:

• IC
• LCM

PINPOINT TEST B: THE INSTRUMENT CLUSTER (IC) ILLUMINATION IS INOPERATIVE 

1. B1 CHECK THE IC FOR CORRECT ILLUMINATION 
   • Key in ON position.
   • Enter the following diagnostic mode on the diagnostic tool: IC DataLogger
   • Command the ILLUMINATE PID to full daytime brightness.
   • Does the IC illuminate correctly? 
   1. YES  : Go to  B3.
   2. NO  : Go to  B2.
2. B2 CHECK FOR CORRECT IC OPERATION 
   • Key in OFF position.
   • Disconnect the IC connector.
   • Check for:
     • corrosion
     • damaged pins
     • pushed-out pins
   • Connect the IC connector and make sure it seats correctly.
   • Operate the system and verify the concern is still present.
   • Is the concern still present? 
   1. YES  : INSTALL a new IC. REFER to INSTRUMENT CLUSTER (IC), MESSAGE CENTER, & WARNING CHIMES 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.
3. B3 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.