CEL should come on if you turn the key to run without actually cranking the engine. This is the bulb test function, and a good idea on a used car. (Shopping tip, it is easier for a used car dealer to remove the bulb than to actually fix a problem
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So if you turn the key on, without the engine running, you should see a CEL. If not, the bulb is burnt out, or disconnnected.
TB
