Trouble codes for 2003 Chevy Blazer

First you need to have EBCM - electronic brake control module check for DTC'S - diagnostic trouble code's . If the light is on there is a code stored . I think most part stores can do this and for free . After you find out what code is stored , looking up that code in service repair information for diagnostic trouble shooting chart would be next step . There are a few codes too.
DTC C0035 or C0040
DTC C0045 or C0050
DTC C0110
DTC C0131
DTC C0161
DTC C0186
DTC C0196
DTC C0201
DTC C0240
DTC C0241 or P0856
DTC C0244 or P1689
DTC C0245
DTC C0283
DTC C0287
DTC C0290 or C0292
DTC C0455
DTC C0550
DTC C0558

Find the code do the diagnostic's , fix the problem , wiring issue's , a sensor , bad module ,what ever it is . The light will go out then . Here is a sample of code discription .
• DTC C0035 Left Front Wheel Speed Sensor Circuit
• DTC C0040 Right Front Wheel Speed Sensor Circuit

Type: OBD & your codes

OBD PO 440
OBD PO128

Codes have nothing to do with installing parts

Codes are System Faults only

Codes are used to diagnose a system & component
test to find a problem

this code does not appear in the GM code list please contact the code reader manufacturer

Just fixed mine with the same code and gm tech advised me to change thermostat which is not a fun job as it is located in the LOWER hose and comes with a gooseneck assembly and O ring.The temp sensor could also be the problem but was told not likely so got by with just thermostat!

Check engine light came on for a reason. Could be one of a hundred reasons. My adivce would be to go to Advance Auto, O'Reilly's or any of the many Parts Stores and "borrow" a Code Reader. Easy to use and most places let you use it for FREE. The Code Reader will show what Code was set and what it MIGHT be. The Code Reader also resets the Codes and the Check Engine Light will go off.... until it senses something is wrong with your truck.

Good Luck.

It is not a carb code as your vehicle has not carburetor. It is an OBD2 ECU code. What is means is that you have an O2 sensor heater circuit malfunction (Bank 2 Sensor 1). In your case I would recommend you inspect all the wiring going to that O2 sensor. If you find no problems then I suggest you replace the O2 sensor. The sensor to replace is on the passenger side, the sensor closest to the engine. This will more than likely fix your problem. After replacing the sensor reset the Check Engine Light. If the problem comes back then seek professional help and do not replace any other parts.

Most major auto part chain stores have a loaner code scanner (they require you to leave your ID while you use the tool in their parking lot). There is a connector under the dash near on the drivers side that accepts the reader....check the codes and Google them for repair info or post them back here.

The are many things that can cause your "check engine" light to stay on. One possibility is that although you have fixed the trouble code for your crankshaft position sensor, the code has not been erased from the computer's memory. Another possibility is that you have another issue going on that is causing a new trouble code to come up. You're going to need to have your car hooked up to a ODB-2 engine code reader to see what the issue is. These code readers are available for purchase at any auto parts store. In addition, many of your local auto parts stores will check trouble codes as a free service to customer. If not, many parts retailers offer the option to rent one of these code readers. Which ever way you decide to go, run a full engine/emissions trouble code check. If the only code that comes up is the code that came up previous to fixing your positioning sensor, then all you need to do is erase the trouble code from the computer's memory. (Most code readers have the option to erase trouble codes, but if you're going to rent or buy one, I would suggest that you check to make sure that the code reader that you're getting is capable of erasing trouble codes as some code readers only indicate the codes and will not remove them from your computer's memory.) If your trouble code scan reveals other codes, then you'll have to fix and erase them as they arise.

FYI- In my experience, I've noticed that 95% of the time that a check engine light/trouble code arises that it is usually an emissions problem (oxygen sensors, mass air-flow units, MAP sensors, etc.). However, General Motors products are notorious for getting trouble codes for having loose battery/ground connections and for having worn-out fuel caps. With any GM vehicle, I always check these two things first to try to save me from having to look further than I need to.

Hope this helps! I'm sure once you've scanned your cars computer and erased any existing trouble codes, that you'll stop being annoyed by your check engine light, as I know how bothersome it can be. Have a great day!

you have a trouble code stored. This means the pcm has detected a problem somewhere