Normal Operation

The check fuel cap warning indicator is used to indicate significant leaks that exceed specifications in the fuel tank evaporative system following fuel system filling. The fuel tank pressure is monitored by the powertrain control module (PCM) and if a leak is detected it signals a fault by sending a message to the instrument cluster over the high speed controller area network (HS-CAN) communication bus. The instrument cluster illuminates the check fuel cap warning indicator. The instrument cluster sets DTC U0100 in continuous memory if the fuel tank pressure status message is missing for more than 5 seconds and the instrument cluster turns off the check fuel cap indicator.

This pinpoint test is intended to diagnose the following:

PCM
Instrument cluster

CHECK FUEL CAP WARNING INDICATOR PINPOINT TEST 9

PINPOINT TEST 9		THE CHECK FUEL CAP WARNING INDICATOR IS NEVER/ALWAYS ON
STEP	INSPECTION		ACTION
1	RETRIEVE THE RECORDED DTCs FROM BOTH THE CONTINUOUS AND ON-DEMAND PCM SELF-TESTS Retrieve the recorded DTCs from the PCM continuous and on-demand self-tests. Are any DTCs retrieved?	Yes	See DIAGNOSTIC TROUBLE CODE (DTC) INDEX - POWERTRAIN CONTROL MODULE (PCM) .
1		No	Go to next step.
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 U0100 retrieved?	Yes	CLEAR the DTCs. REPEAT the self-test. If DTC U0100 is retrieved again, go to INSTRUMENT CLUSTER DIAGNOSTIC TROUBLE CODE (DTC) INDEX .
2		No	Go to next step.
3	CARRY OUT THE INSTRUMENT CLUSTER INDICATOR LAMP 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 check fuel cap indicator (FUEL_CAP) active command. Command the check fuel cap indicator on then off. Observe the check fuel cap indicator. Does the check fuel cap indicator turn on when commanded on and turn off when commanded off?	Yes	Go to next step.
3		No	Go to step 5.
4	CHECK FOR CORRECT PCM OPERATION Disconnect all the PCM connectors. Check for: corrosion damaged pins pushed-out pins Connect all the PCM 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 PCM. See POWERTRAIN CONTROL MODULE (PCM) REMOVAL / INSTALLATION . TEST the system for normal operation.
4		No	The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
5	CHECK FOR CORRECT INSTRUMENT CLUSTER OPERATION Disconnect all the instrument cluster connectors. Check for: corrosion damaged pins pushed-out pins Connect all the 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.
5		No	The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.