2002 CHEVY TRAILBLAZER keeps setting a FAN Speed Sensor Code.

It's the throttle position sensor (TPS) on the throttle body.

2 different problems....106 is MAP sensor code, clean your throttle body with the battery disconnected. 526 is fan speed sensor. There is a common problem with the connector that goes into the fan clutch. Check for frayed wires here or burnt connector, if all ok, may need new fan clutch.

See attached picture for location of temp. sensor, but that code has nothing to do with temp sensor. The speed of the fan does not agree with the commanded speed, you may have another bad fan clutch.

Sounds like the fan clutch is going bad, these had a reputation for failing. The fan clutch is controlled by the computer and if the fan speed does not match what the computer has set, an error code is set. A fan clutch costs in the area of $120 - $200, and the labor to replace it is probably another equal amount.

The throttle body needs to be cleaned, grime in this area prevents the throttle plate from closing completely and allowing air to enter, making the air/fuel mixture lean.
Code P0526 is related to the fan clutch, it indicates that the fan speed is not what the PCM commanded. The fan clutch may have to be replaced.

My 2002 Chevy TrailBlazer sounded like a jet taking off...it was the clutch fan.

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!!

your code P1481 is for the cooling fan speed the problem is often the wires and connector that go to that unit ... removing and replugging the connector sometimes fixes it ... also check the fan clutch and fan (not as often the trouble) .. there is a techniical bulliten out for this trouble .. (tsb050605012) .. sometimes the wire harness is replaced for the fan ...

your trouble code p1271 is associated with the accelerator pedal position sensor (APP) (right above the gas pedal) .. again check the wiring and connector going to the APP .. if the APP turns out to be bad then its not hard to change and requires no computer changes ... when you get an APP alarm then your car may go into a "reduced speed mode" ...
here is a list of the service bullitins on your trailblazer....

http://www.carcomplaints.com/Chevrolet/Trailblazer/2002/tsbs.shtml

Hi.
The cooling fan speed sensor is built in inside the fan clutch.
If you have a code p1481 or similar , pointing at the cooling fan speed sensor, often you have to fix or replace the wiring , rather that the sensor.
Check that wiring has continuity, the wire to sensor must have +5V. Here an interesting website on trailblazer fan system.
Regards.

sounds like fan clutch.