Intermittent Fan control

[Badunit]

I am having an intermittent blower motor problem on my JT where about half the time when I start my truck it is stuck on fan speed 1 and the fan speed knob has no effect. Other times it works perfectly fine. It is a toss up which it will be when I start my truck but, whichever it chooses, it stays that way until I start it again. I'm at a loss as to what the problem could be. I hope someone here can help.

I have an Icon T10 and have done the following diagnostics:

1. Read codes. There are none.
2. Watched live data of the blower control knob, blower speed, and blower PWM as I turned the fan knob. The knob position is recognized regardless of whether the blower reacts to it or not. The knob position is also displayed on the UConnect and it, too, recognizes it. The blower speed and PWM remain static (equivalent to level 1) when it is not working correctly. They go up and down as they should when it is working correctly.
3. Controlled the fan speed knob though the T10. The blower speed changes if I set the knob position in the T10. After cancelling the control, the actual knob still does not work.
4. Controlled the fan speed though the T10. The blower speed changes correctly when I control it through the T10. After canceling the control, it goes back to fan speed 1 and the actual knob still does not work.

It seems that each individual part is working correctly. The knob is apparently communicating on the bus, at least to the point that the UCONNECT and OBD port can see it. The heater module controls the blower and obeys fan knob commands when sent from the OBD port. What the heck would cause the heater control to not hear (or not obey) commands from the fan knob?

Sponsored

 

[bmpcamry09]

I’d pay your local dealer a visit and see if there are any HVAC module updates available

 

[Badunit]

Visiting dealer is what I am trying to avoid, even though it is still under warranty. Visiting them without first knowing what needs to be fixed/replaced is the worst. Lord knows what they'll tear apart and half-ass replace. I'd rather pay for a part and replace it myself, if I knew what part. HVAC module, STAR connector, center stack, UConnect (not paying for that!), or something else? I don't want to do a parts cannon on it, though.

One thing I forgot to mention is that controlling the fan though the UConnect climate controls has the same problem as the knob.

 

[bmpcamry09]

That’s why I’m saying have them check the HVAC modules and all the other modules for software updates. Unless you can find an independent shop with wiTech

 

[zouch]

just curious; what happens if you use the 'Auto' setting for the Fan speed?
almost sounds like yours is on Auto, and it's not commanding any higher speeds.

I am having an intermittent blower motor problem on my JT where about half the time when I start my truck it is stuck on fan speed 1 and the fan speed knob has no effect. Other times it works perfectly fine. It is a toss up which it will be when I start my truck but, whichever it chooses, it stays that way until I start it again. I'm at a loss as to what the problem could be. I hope someone here can help.

I have an Icon T10 and have done the following diagnostics:

1. Read codes. There are none.
2. Watched live data of the blower control knob, blower speed, and blower PWM as I turned the fan knob. The knob position is recognized regardless of whether the blower reacts to it or not. The knob position is also displayed on the UConnect and it, too, recognizes it. The blower speed and PWM remain static (equivalent to level 1) when it is not working correctly. They go up and down as they should when it is working correctly.
3. Controlled the fan speed knob though the T10. The blower speed changes if I set the knob position in the T10. After cancelling the control, the actual knob still does not work.
4. Controlled the fan speed though the T10. The blower speed changes correctly when I control it through the T10. After canceling the control, it goes back to fan speed 1 and the actual knob still does not work.

It seems that each individual part is working correctly. The knob is apparently communicating on the bus, at least to the point that the UCONNECT and OBD port can see it. The heater module controls the blower and obeys fan knob commands when sent from the OBD port. What the heck would cause the heater control to not hear (or not obey) commands from the fan knob?

Sponsored