Four problems related to service engine light on have been reported for the 2004 Chevrolet Trailblazer. The most recently reported issues are listed below.
Engine started misfiring on random cylinders,misfire does not stay on same cylinders. Has dramatic loss of power. Diagnostic code says random misfire. Dramatically decreased fuel economy. Bad vibration. Service engine light flashes during misfire. Does not have a constant misfire, it comes and goes.
The contact owns a 2004 Chevrolet trailerblazer. The contact stated that the service engine light illuminated while driving. The vehicle was taken to a mechanic who stated that the failure code indicated that the thermostat was defective. Within a few days all of the lights on the instrumental panel illuminated. The vehicle was taken back to the mechanic and there was no diagnostic code displayed. The failure occurred intermittently. The vehicle wasn't repaired. The failure and the current mileages were 74,393.
Service engine soon light was on after completing a diagnostic test at a local dealer they said the malfunction was the secondary air injection(air pump) code p0410. They said the reason these go out is because of an engineering defect and the way they routed the hoses instead of air flowing through it causes water to accumulate therefore making the motor in the air pump to go bad. So while changing out this bad air pump there was so much water that had accumulated it actually caused the light to blow which could have caused the mechanic to be electrocuted!.
We have had a problem with our service engine light coming on within the past 2 weeks in our 2004 Trailblazer. After getting it diagnosed it is being caused by the fan speed being too high. After doing some research this vehicle has had numerous repairs for the same issue. Why has gm not warranted this!? we have gotten crappy service from the dealership and while our vehicle is out of warranty now it is paid for our we would have gotten rid of it already.