Normal Operation

NOTE:

The smart junction box (SJB) is also known as the generic electronic module (GEM).

The fog lamp indicator informs the driver that the fog lamps are on. The instrument cluster receives the fog lamp status from the SJB/GEM over the high speed controller area network (HS-CAN) communication bus. When the headlamp switch is in the parking lamps ON position and the fog lamp switch is in the ON position, the SJB/GEM enables the fog lamp relay. When the fog lamp relay is enabled, the SJB/GEM sends a message to the instrument cluster to turn on the fog lamp indicator.

DTC U0140 (Lost Communication With The Body Control Module [GEM]) - is a continuous DTC that sets in the instrument cluster if the fog lamp status message is missing for more than 5 seconds and the instrument cluster turns off the fog lamp indicator.

This pinpoint test is intended to diagnose the following:

SJB/GEM
Instrument cluster

FOG LAMP INDICATOR PINPOINT TEST 26

PINPOINT TEST 26		THE FOG LAMP INDICATOR IS NEVER/ALWAYS ON
STEP	INSPECTION		ACTION
1	CHECK THE FOG LAMPS OPERATION Key in ON position. Place the headlamp switch in the PARKING LAMPS ON position. Place the fog lamp switch in the ON position. Do the front fog lamps operate correctly?	Yes	Go to next step.
1		No	See FOG LAMPS .
2	RETRIEVE THE RECORDED DTCs FROM BOTH THE CONTINUOUS AND ON-DEMAND INSTRUMENT CLUSTER SELF-TESTS Retrieve the recorded DTCs from the instrument cluster continuous and on-demand self-tests. Is DTC U0140 retrieved?	Yes	If DTC U0140 is retrieved, CLEAR the DTCs. REPEAT the self-test. If DTC U0140 is retrieved again, go to next step.
2		No	Go to step 4.
3	CHECK THE NETWORK OPERATION Enter the following diagnostic mode on the scan tool: Network test Does the SJB/GEM pass the network test?	Yes	Go to step 5.
3		No	DIAGNOSE the module communication network. See PINPOINT TEST 5: NO CONTROLLER AREA NETWORK (CAN) COMMUNICATION .
4	CARRY OUT THE INSTRUMENT CLUSTER INDICATOR LAMP CONTROL ACTIVE COMMAND USING THE SCAN TOOL Key in ON position. Enter the following diagnostic mode on the scan tool: Instrument Cluster DataLogger Select the instrument cluster fog lamp indicator (INDICATOR) active command. Command the fog lamp indicator on then off again. Observe the fog lamp indicator. Does the fog lamp indicator illuminate when commanded on and turn off when commanded off?	Yes	Go to next step.
4		No	Go to step 6.
5	CHECK FOR CORRECT SJB/GEM OPERATION Disconnect all the SJB/GEM connectors. Check for: corrosion damaged pins pushed-out pins Connect the all the SJB/GEM 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 SJB/GEM. See SMART JUNCTION BOX (SJB) . TEST the system for normal operation.
5		No	The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
6	CHECK FOR CORRECT INSTRUMENT CLUSTER OPERATION Disconnect all instrument cluster connectors. Check for: corrosion damaged pins pushed-out pins Connect all instrument cluster 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 instrument cluster. See INSTRUMENT CLUSTER . TEST the system for normal operation.
6		No	The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.