Code Questions

[doobismaximus]

Im getting code 564. Which is fan control circuits failure. The fan runs as i start the test, i assume it works as needed. Dont have any fuses that are blown. Could it be the connection from harness to fan?
Also getting 176,172. Which are lean o2 sensor codes. I replaced both sensors a little over a year ago. Does any one have an idea why its running lean? Need ass-sistance

 

[toyman]

Look for any breaks in the vacuum system and air being drawn into the exhaust system before the O2 sensors. Check the fan operation at the fan motor pigtail by supplying power directly from the battery positive terminal. There are three pins, high and low fan and a ground. If that checks okay it's likely the fan control circuit in the CCRM is the source of the code.

 

[doobismaximus]

Is this important?

 

[toyman]

Might be. Where does it go at the other end of the tubing? Looks like it's been capped off.

 

[doobismaximus]

It goes through the firewall from the engine bay. Where it originates, i havent the foggiest. Cant tell if its been shortened. Im gonna check the window washer fluid tomorrow. As thin as it is, it cant be doing much. Will do some more investigation tomorrow.

 

[toyman]

The other end is probably connected to the HVAC control. Do you get hot and/or cold air from the vents?

 

[doobismaximus]

Heat works good. Ac is working also. Im getting my truck out of the shop tomorrow. So i can do some real investigation then. For now it will have to wait. Thanks for your input tho bro

 

[Chythar]

That line is probably the one that provides vacuum to the HVAC controls behind the dash. Do you only get air through the defroster vents? That line should lead across the firewall to the vacuum tree on the driver's fender, right next tothe brake booster. It's the small connector, third from the top.