One problem related to check engine light on has been reported for the 2003 Chevrolet Suburban. The most recently reported issues are listed below.
Vehicle stalls at highway speeds, specifically, under load (up hills, accelerating, etc. . . ) when gas is given, the car stalls. The tach still reads a number, and all cabin electronics remain active, without showing any hint of a problem (no spike, dimming of lights, etc. . . ) engine just dies. (again, this typically happens at highway speeds [40-80 mph. ]) no check engine light comes on, and there is no indication of the possibility of a failure electronically [ie, no "messages. "] the only discernible symptom is sluggishness on the part of the accelerator, as if slamming the accelerator to the floor would cut out the engine, but slowly pushing the accelerator to the floor would permit (somewhat) the acceleration. (mind you, that I almost never push my accelerator all the way to the floor. ) further, any acceleration (however slight,) can cause the engine to stall when the car is in the mood to want to stall. (the problem is somewhat intermediate - it has happened about 10-15 times in the past 6 months, once on the throgsneck bridge in NY. ) the problem has happened on numerous occasions, (the first time around the beginning of July '06, [about 2 occasions on one day, 4 more another day that week,) and then again around October 10th, on which there were another 5 or so incidents. On oct 11th, I brought the car back to the dealership, and they saw no error codes, so couldn't do anything to diagnose the problem. Onstar was similarly unable to diagnose any errors with the vehicle.