My Truck Is Sending Me Morse Code!

[solarjustin]

So I was driving around town this weekend and my truck just keep making this ticking sound from under the dash. So I started to play around with things trying to figure out what was making this sound, well I had my HVAC set to blow only on my front window, now the second I turned it off to window and feet or any other setting it stopped making the ticking sound. Now I have heard this sound once before, but didn't think much of it(short drive). Has anyone else had this problem and know of any fixes.

 

In case it matters I have a 2004 1500 Ext, 2wd with the 4.8L. I live in Iowa so I hope their is something I can do so it does not tick in drfrost mode, being I park outside all the time, this fuction will be used often in the up coming months.

[NothinButBowTies]

Mine does the same thing. I would love to know what is wrong with it.

[99silverado1500]

Supposedly its the gears grinding when it changes vent settings for the AC.

[solarjustin]

Mine only does it in defrost mode, is the moter just over driving the gear?

[Rwayne]

Ya I have the same problem. I crawled underneath the driver side dash and it seems to be coming from the ac vents, maybe grinding in the gears like 99silvy said. Is this something that can be fixed reasonably, or just an annoyance that's cheaper to live with?

[solarjustin]

What really bugs me about it is that ti will not always make the noise, so it is hard to track it down. Always seams to make the noise when I don't have time to look at it.

[Rwayne]

Well the first time I heard it I climbed under the dash immediatley because I had just bought the truck.. and I know mine is coming from the ac. I had a friend turn it off while I was under the dash and noticed it right away. But your right, it doesn't always do it. I've only had my truck for about a month now. It seems to do it when I change the direction of flow when i'm on the highway... Oh and a quick question, I have the climate control, and when I turn it off with the air coming out of the dash vents it seems to default back to the ground vents when I go to turn it back on..is this normal?

[solarjustin]

Man you guys are letting me down! Does no one else have this problem and know of a way to fix it?

[unit731]

2005 Silverado Extended Cab.

 

Neighbor of mine has same problem. A ticking from the dash. Not all the time. He is baffled too!

 

He'd like the answer too !

[davo32683]

Same problem here, I've just learned to turn up the radio to ignore it!

[unit731]

Has an answer been determined for this ticking yet?

[jrrod2004]

Here is some info for your trucks:

 

 

 

Document ID# 1822804

2004 Chevrolet Chevy C Silverado - 2WD

Subject:Intermittent Ticking Noise from I/P, Poor A/C Performance, HVAC DTCs B0229, B0414, B0424, B3770, (Reprogram HVAC Control Module) #06-01-38-003 - (04/27/2006)

Models:2004-2006 Cadillac Escalade Models

 

 

2004-2006 Chevrolet Avalanche, Silverado, Suburban, Tahoe

 

 

2004-2006 GMC Sierra Models, Yukon Models

 

 

with Air Conditioning (RPOs CJ2, CJ3)

 

 

Condition

Some customers may comment on one or more of the following concerns:

 

 

• Intermittent ticking/clicking noise from the instrument panel.

 

 

• Recirculation mode does not work or Air Conditioning (A/C) system performance is poor during high ambient temperatures.

 

 

• Unable to control the driver side temperature.

 

 

• Unable to control the passenger side temperature.

 

 

• Unable to change the front system modes.

 

Cause

This condition may be caused by the Heating, Ventilation and Air Conditioning (HVAC) actuators that may hunt for the correct commanded position. This cycling may cause a clicking or ticking noise.

 

An overtravel of the HVAC system control doors may cause one or more of the concerns listed above. If an overtravel occurs, a Diagnostic Trouble Code (DTC) will be set, and the door will go to a preset default position. When a system door defaults, that door will stay at the default position until the DTC is cleared. After the DTC is cleared, the door will operate properly until the overtravel condition re-occurs.

 

The following table lists the HVAC system doors and the DTC associated with it.

 

System Door

 

Overtravel DTC

 

Air inlet door (recirculation door)

 

B0229

 

Left temperature door

 

B0414

 

Right temperature door

 

B0424

 

Front system mode door

 

B3770

 

Correction

Technicians are to perform the normal diagnostic procedures in SI for these concerns. If diagnostics show that the HVAC system door(s) travel below 5 counts (out of the lower range) or above 250 counts (out of the upper range), then update the software calibrations in the HVAC control module. The new calibrations were made available to dealerships as part of TIS2000 incremental satellite update version 2.5, which was broadcast to dealers in February 2006.

 

The new calibrations have been updated to compensate for the actuator overtravel condition, the actuator hunting and the ticking/clicking noises. The new calibrations effectively eliminate the codes listed above, the default position of the doors associated with the DTCs and opens up the feedback position value. The new calibrations should not be used unless the vehicle has one or more of the customer concerns listed above or a DTC listed above has been set. The new calibrations will not correct any other DTC or A/C system performance concern.

 

Warranty Information

For vehicles repaired under warranty, use:

 

Labor Operation

 

Description

 

Labor Time

 

D4707

 

HVAC Control Head Module or Assembly Reprogramming with SPS

 

Use Published Labor Operation Time

 

 

 

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

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Hopes this helps out everyone who is having this problem