cmittag

I have a 1982 Collector Edition. When I turn off the ignition the check engine light comes on. Any ideas why? Is there a easy way to correct this?

Bangkok Dean

Welcome to the C3 gang The most knowledgeable guy for 82s is Twin Turbo, he may chime in here or some others that have experience with this problem.

Desertdawg

Is the light coming on? and staying on with the key removed???

cmittag

Light goes out with ignition on and running and comes on with ignition off and key out.

Twin_Turbo

The most plausible cause would be that someone has changed the 12v switched power lead to a non ignition switched source, either directly to the battery orjunction block right next to it or in the harness between the ecm and fusebox.

The ECM has 2 power leads, an ignition switched main power lead and a ram power lead which is non switched off the junction block, this one is for the ram memory, an orange wire sometimes with an inline fuse. This one seems fine since without it the CEL won't light at all.

Is this something that happened recently?

Is the CEL the only thing that has power to it with the ignition off?? If not, it could also be your ignition switch

cmittag

I'm using a battery disconnect to keep from bleeding the battery.

The car has not been worked on and this started before I installed the disconnect.

It started about six months ago and would go away for a while. Now the light is on when there is battery power and no key in the ignition.

Nothing else is powered with the ignition off.

cmittag

When I turn on the ignition the light goes off.

Bangkok Dean

Now that sound interesting

cmittag

Is the ECM the box forward of the Battery?

Twin_Turbo

yes and the ESC is bolted to the back of the ECM (on the firewall behind the seats side)

cmittag

Not to sound dumb, but what is the ESC?