: Tighten Gas Cap



Asguard726
08-23-13, 12:05 AM
Hi guys, had a "Tighten Gas Cap" message come up on the instrument cluster screen. Stopped and checked, cap was tight. Warning went away.
Came back on a week later and this time the check engine light came on as well. Requested the On-Star diagnostic and the nice lady said tighten
cap two clicks and light should go off within seven days of normal driving?? That did not sound right so after 3 days I went on down to the dealer.
Turns out cap was fine but purge valve was bad. They replaced it and it was covered under the certified warranty as I've now got 55,000 miles on
the clock of my '09. Just thought I'd mention as an FYI to anyone else who might encounter this message.
Cheers, Dan

Submariner409
08-23-13, 08:54 AM
EVAP system faults and the resulting common "Check Gas Cap" message are discussed at length in Cadillac Tech Tips and Northstar Performance.

A common fault is the EVAP purge line where it attaches to the purge valve at the right (rear) side of the throttlebody. Another is the lines connected to the charcoal canister under the frame rail just under the rear seat driver's side.

Cadillac Cust Svc
08-23-13, 09:53 AM
Hi guys, had a "Tighten Gas Cap" message come up on the instrument cluster screen. Stopped and checked, cap was tight. Warning went away.
Came back on a week later and this time the check engine light came on as well. Requested the On-Star diagnostic and the nice lady said tighten
cap two clicks and light should go off within seven days of normal driving?? That did not sound right so after 3 days I went on down to the dealer.
Turns out cap was fine but purge valve was bad. They replaced it and it was covered under the certified warranty as I've now got 55,000 miles on
the clock of my '09. Just thought I'd mention as an FYI to anyone else who might encounter this message.
Cheers, Dan

Hello Dan,

I appreciate you taking the time to post this concern and its outcome. I am sure other members will appreciate it if they encounter a similar situation. I am glad you were able to have the dealer locate your vehicle issue and replace the valve that was bad. I hope everything is operating great for you now. If any other concerns or questions arise, don't hesitate to contact us!

Regards,

Laura M.
Cadillac Customer Care