Check engine light come on and off on my 2004 trailblazer

SOURCE: 2005 trailblazer check engine light on

Verify any "check engine" by first resetting the computer then waiting to see if it returns. To reset the computer, disconnect the battery cable (some say either cable, I say positive{red} cable). Leave the cable disconnected for about 30 minutes then reconnect it and start the engine. Because the cable was disconnected from power for a while, the computer will have to reboot upon startup. Just like any computer, sometimes a reboot will solve the hangup. If the error returns, it is likely a sensor is bad or the sensor is indicating a true problem.

SOURCE: CHECK ENGINE LIGHT ON AND REDUCED POWER LIGHT ON,

Replace your throttle position sensor, runs about $60.00 sit on throttle body has a round connector with three wires going o it.

SOURCE: chevy trailblazer check engine light

P0128 is coolant operating temperature operating too low. This can be contributed to the Thermostat stuck open or faulty electronic radiator fan clutch. This is common, I had the same issue and replaced the thermostat and fan clutch and had the clutch re-programmed (required) at the dealer. As for the P0410, check the air pump fuse, if blown it will set this code on. Also check the air pump hoses for water and cracks. Hopefully this helps!!

SOURCE: What is code 455 (Check

CODE PO455 - EVAP SYSTEM LARGE LEAK DETECTED CONDITIONS.POSSIBLE CAUSES FUEL CAP LOOSE MISSING,FUEL TANK FULLER NECK OR FUEL SENDING UNIT O - RING IS LEAKING, FUEL TANK PRESSURE SENSOR IS DAMAGED,FUEL TANK VAPOR LINES,CLOGGED,DAMAGED,OR DISCONNECTED,PURGE VALVE VAPOR LINE IS CLOGGED,DAMAGED,OR DISCONNECTED,PURGE SOLENOID IS NOT OPENING,IT MAY BE DAMAGED OR STICKING,VENT SOLENOID IS NOT CLOSING,MAY BE DAMAGED OR STICKING,PCM HAS FAILED.

Ryan Lutton

• 1267 Answers
• Posted on May 31, 2011

SOURCE: 2004 trailblazer, 2 wheel drive.

A couple of things come to mind. Double check the wiring at the fan clutch, check the whole harness, there is a known problem wth chaffing there. Is it a Dorman brand fan clutch? These have been known to be bad out of the box. The other thing that could be wrong is the actual speed sensor on the new fan clutch. Hope some of this helps.