HELP!!! I Have a 2008 HHR 2.4. The check engine light doesn't come when the key is turned to the auxiliary position. This is keeping me from passing smog. The mechanic has tried replacing the cluster 3 times now. Same problem. All other warning lights and such display just fine. Counting the original cluster this means 4 clusaters have all had the same problem He says he has done the appropriate wiring/ground checks and everything is good. What can be the problem/solution?

 

The Check Engine Light does not come on in the Accessory position. You have to turn it to the On position.

Your problem may be as simple as a blown fuse to the power outlet. That fuse (#29) powers the outlet and the OBD receptacle.

Why in the world would someone replace the instrument panel 3 times if it didn’t fix it ? Pretty obvious that was a wrong diagnosis.
Find a new mechanic.

 

You're right. It is the on position not accessory position. It is possible to have gotten bad replacement parts seeing as we are talking used parts not new. But 3rd time is my limit and if nothing else comes of the mechanics research I will take your advise.

 

But. What about fuse #29 ?

The chances of getting 3 bad instrument panels is almost nil.

 

Check the brn/wht wire on pin #11 on the cluster, the other end is pin #12 on connector C1 on the ECM, that is the ground/control the other side of the LED goes to B+ via some sort of "logic" in the cluster.
Does the mechanic have a computer to match the new clusters to the BCM? If he does he should be able to check the 1 LED on the cluster. Without matching the odometer will not work another reason to flunk inspection..

 

Even when the parts are coming from salvage yards as no new clusters are manufactured or in any warehouse shelves?

Mechanic says he checked #11 pi9n wire. It's good.

 

If you are referring to fuse panel in passenger side of consol, #29 is marked pwr wndws.

 

Under hood fuse box. And read my post #2 again.

#29 in the interior fuse box is not the power windows fuse. Pretty sure that fuse slot is labeled “empty “.

 

2008 owner manual says #29 interior fuse block is indeed power windows

But yes #29 underhood fuse block is power port (and OBD2 port).

 

judging by the fact that you recently registered - you recently purchased this car ...
I do not want to act as an accuser, just a thought out loud:
unscrupulous sellers sometimes turn off / remove "the check engine" light so that a potential buyer does not see a clear problem and pay an unreasonable price.