Code PO526?

CHITOWNOLSON

MEMBER
2006 CHEVROLET TRAILBLAZER
4.2L
V6
2WD
AUTOMATIC
150,000 MILES

So, the cooling fan and water pump have been changed, wiring harness was also changed but I notice there looks to be two gray wires. Could those be wired wrong and could that throw the po526 code. If not, how do I test and identify all 5 wires so I can mire it correctly?

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,747 POSTS

Hi,

You are correct. There are two wires. One is a low reference and the other is power supply. I would think if they were switched, it would cause the fan fuse to fail, but anything is possible.

I attached the wiring schematic below, so you have a reference. To make it readable for you, I had to cut it in half. I did overlap the two so you can follow from one to the next. (Pics 1 and 2)

The remaining pics are the diagnostics related to the code. Keep in mind, the code is set because the PCM determined the fan is not turning fast enough for the conditions. So, you have already replaced the fan, so there is a change it is wire related or the cooling fan speed circuit. Actually, if the belt is removed and the engine started, it would set this code.

Take a look through the diagnostics and let me know if you are comfortable performing them.

Take care,

Joe

See pics below.

Images (Click to make bigger)