Join Date: Mar 2007
Location: Lake Havasu City, Arizona
Own a Commander?: Yes
Model year: 2006
Trim Package: Sport
If 4WD - system: QD-II
Current Mileage: HueyPilotVN
I went thru the manual and found this:
GAS CAP INDICATOR
A gas cap indicator is standard equipment on all instrument clusters. However, on vehicles equipped with the
optional diesel engine, this indicator is electronically disabled. The gas cap indication appears within the reconfigurable
dot matrix Organic Light Emitting Diode (OLED) display unit. The gas cap indicator consists of a textual
CHECK GAS CAP message which appears in place of the compass/trip computer information in the dot matrix
The dot matrix OLED is soldered onto the cluster electronic circuit board, and is visible through a window with a
smoked clear lens located on the lower edge of the tachometer gauge dial face of the cluster overlay. The dark lens
over the OLED prevents it from being clearly visible when it is not illuminated. The gas cap textual message
appears in the same blue-green color and at the same lighting level as the compass/trip computer information when
it is illuminated by the instrument cluster electronic circuit board.
The gas cap indicator is serviced as a unit with the OLED in the instrument cluster.
The gas cap indicator gives an indication to the vehicle operator when there is a gross leak detected in the onboard
fuel vapor recovery system. This indicator is controlled by the instrument cluster logic circuit based upon
cluster programming and electronic messages received over the Controller Area Network (CAN) data bus from the
Powertrain Control Module (PCM).
The gas cap indicator function of the reconfigurable dot matrix Organic Light Emitting Diode (OLED) display unit is
completely controlled by the instrument cluster logic circuit, and that logic will only allow this indicator to operate
when the instrument cluster receives a battery current input on the fused ignition switch output (run-start) circuit.
Therefore, the OLED gas cap indication will always be OFF when the ignition switch is in any position except ON
or START. The instrument cluster will turn ON the gas cap indicator for the following reasons:
² Gas Cap Indicator Lamp-On Message - Each time the cluster receives an electronic gas cap indicator
lamp-ON message from the PCM indicating there is a gross leak in the vapor recovery system, the gas cap
indicator will be illuminated. The indicator remains illuminated until the cluster receives a lamp-OFF message
from the PCM, or until the ignition switch is turned to the OFF position, whichever occurs first.
The PCM continually monitors the on board vapor recovery system to determine whether there are air leaks in the
system. The PCM then sends the proper lamp-ON or lamp-OFF message to the ElectroMechanical Instrument Cluster
(EMIC). If the EMIC turns ON the gas cap indicator due to a monitored gross leak in the vapor recovery system,
it may indicate that the gas cap has been removed or is improperly installed.
For proper diagnosis of the on board vapor recovery system, the PCM, the EMIC, the CAN data bus or the electronic
communication related to gas cap indicator operation a diagnostic scan tool is required. Refer to the appropriate
Maybe the compressor that he was referring to is the vapor recovery pump.
2007 Jeep Green Limited 4.7 Flex Fuel, RR 2.5" 4 inch Superlift coils on rear, 1.5" Spacers, Bridgestone 265/70/17, K&N CAI, Flowmaster, Diamond Plate Locking Trunk, Blue Ox Baseplate w/D-rings, "Get Lost 4X4" Front Bumper, T-Max 9000 winch, "Get Lost rear tire carrier, 30 gal second gas tank.
Second 2007 Jeep Green Limited Leather HEMI QDII VES Uconnect Flowmaster OEM Skids Tow Package
Maybe the two will meet up soon edit: they did , I now have 2,now gave 1 away...and got it back again.
Last edited by HueyPilotVN; 02-03-2009 at 01:31 AM.