Check engine light (CEL) is on. The vehicle is a 98 ML-320.

A dump of the computer's error codes indicates that I have two problems.

The first is "Injector Circuit - Cylinder 12."
The second is "Engine Shutoff Solenoid."

The Cylinder 12 code is a real stumper. I can find but 6 cylinders under the hood. Where did those Alabamaniacs put the other 6?

As for the Engine Shutoff Solenoid, I can not identify this part.

I can find two "Engine Shut-off Valves. " These, however, are not solenoids but vacuum valves. They appear to be working normally.

Does anyone have a clue as to what is wrong with my engine? I have reset the CEL now three times. The time and mileage between resets varies. It seems the CEL comes on after going over a speed bump in a parking lot.

By the way, the engine appears to be preforming just fine. Power, acceleration, gas mileage, appear normal. Idle speed may be low (600 rpm), conditions are engine is hot, idling in gear, brake on.