brianfromhawaii

iTrader: (3)

Bought a 2002 z28 yesterday, automatic trans, nice car... i brought my laptop with HPtuners to scan it and saw it had a brake code goin on, and I was like eh whatever for the price I dont even care!

Last night was driving along and stopped to get gas, and when I got back in the car I noticed the AC was no longer blowing out of the top vents it was coming out of the foot vents, I tried changing it to every setting, no difference... So I was like thats odd, then I noticed the service engine soon light was on and gave me these codes

[Brake] C0550 - ECU Malfunction (Current) This was always there...
[HUD] B1000 - ECU Malfunction (History) (Immature)
[HUD] U1000 - Class 2 Communication Malfunction (History) (Immature)

Hopin someone can help me out so I can get my AC back to normal, maybe even fix the brake problem?

brianfromhawaii

iTrader: (3)

wanna add that I just took it for a drive, and after 10 minutes of driving the AC started coming from the right vent and the codes were gone, then after 30 min of that or so working right it went back to bein messed up

2001NBMZ28

The vent controls are vacuum operated, blowing out the feet/dash is the default mode. Check the vacuum lines from behind the intake over towards the passenger side.

brianfromhawaii

iTrader: (3)

see i thought about that, but how come it throws a code when that is happening?

2001NBMZ28

There are specific AC codes, but they don't illuminate the SES light, just stored. It was still blowing cool right, just not blowing out the correct vents? Still think it's a vacuum issue.

brianfromhawaii

iTrader: (3)

it was blowing cold, yes.... maybe something is pinching the vacuum hose.. ill have to do some hunting

Ruthless909

iTrader: (19)

Don't mean to thread jack but I recently purchased a 2001 Camaro Z28 and the AC starts blowing through the foot vents aswell.

Weird...

SS SLP2

iTrader: (8)

^^^^ I agree, THAT hose (does switch the output) is hard to reach,but can be done by laying on top of intake and reaching around behind intake
been there and done that.... several times
have fun ,Johnny

brianfromhawaii

iTrader: (3)

line is on for sure, checked the T right by the computer, its got vacuum there too, any other ideas?

brianfromhawaii

iTrader: (3)

i lift weights a bit, so my arms were way too big to even fit.. i did get my gf to make sure it was on there for me though.... she is handy after all!

CalEditor

iTrader: (1)

Air Distribution -- Front Control
Mode Switch
Use the MODE switch in order to change the air delivery mode in the vehicle. The air flow direction will sequence through the following modes:

• MAX A/C

• A/C

• BI-LEVEL

• VENT

• FLOOR

• MIX-BLEND

• FRONT DEFROST

Max A/C Mode
When the driver selects the MAX A/C mode, the blower motor and A/C compressor clutch are activated. The recirculation door is activated, bring air from inside the vehicle for maximum cooling. Air is delivered out the instrument panel outlets with a small amount out the floor outlets. Vacuum is applied to the mode actuator through the Violet vacuum line, and to the defrost actuator through the Yellow vacuum line. The mode actuator will retract, opening the Vent Door. The defroster actuator will retract, closing the Defroster Door and open the Heater Door through mechanical linkage.

A/C Mode
When the driver selects the A/C mode, the blower motor and A/C compressor clutch are activated. Outside air is brought in to be cooled. Air is delivered out the instrument panel outlets with a small amount out the floor outlets. Vacuum is applied to the mode actuator through the Violet vacuum line, and to the defrost actuator through the Yellow vacuum line. The mode actuator will retract, opening the Vent Door. The defroster actuator will retract, closing the Defroster Door and open the Heater Door through mechanical linkage.

Vent Mode
When VENT is selected, air is delivered through the instrument panel outlets with a small amount of air delivered to the floor. Vacuum is applied to the mode actuator through the Violet vacuum line, and to the defrost actuator through the Yellow vacuum line. The mode actuator will retract, opening the Vent Door. The defroster actuator will retract, closing the Defroster Door and open the Heater Door through mechanical linkage.

Bi-Level Mode
When Bi-Level is selected, air is delivered through the instrument panel outlets and to the floor outlets. Vacuum is applied to the mode actuator through the Violet and the Green vacuum lines, and to the defrost actuator through the Yellow vacuum line. Applying vacuum to both sides of the mode actuator will hold the Vent Door stationary in the half open position. The defroster actuator will retract, closing the Defroster Door and open the Heater Door through mechanical linkage.

Floor Mode
When Floor is selected, air is delivered to the floor outlets. Vacuum is applied to the mode actuator through the Green vacuum line, and to the defrost actuator through the Yellow vacuum line. The mode actuator will retract, closing the Vent Door. The defroster actuator will retract, closing the Defroster Door and open the Heater Door through mechanical linkage.

Mix-Blend Mode
When Mix-Blend is selected, air is delivered to the windshield outlets and the floor outlets. Vacuum is applied to the mode actuator through the Green vacuum line, and to the defrost actuator through the Yellow and the Red vacuum lines. The mode actuator will retract, closing the Vent Door. Applying vacuum to both sides of the defroster actuator will hold the Defroster Door stationary in the half open position. The Heater Door will also be held stationary in the half open position through mechanical linkage.

Defrost Mode
When Defrost is selected, air is delivered to the windshield outlets. Vacuum is applied to the mode actuator through the Green vacuum line, and to the defrost actuator through the Red vacuum line. The mode actuator will retract, closing the Vent Door. The defroster actuator will retract, opening the Defroster Door and close the Heater Door through mechanical linkage.

CalEditor

iTrader: (1)

I sent you an email also

coD

The vehicle does not happen to have the "hide the wires" over the passenger side engine fender does it? There is an accumulator canister that can be accessed via the front passenger side underside plastic splash guard-two 10mm bolts. Easy to pinch, pull off a line down there too.

Texas_WS6

iTrader: (9)

You said there was a brake code too? Do the brakes feel hard to push? Being you just got the car you might not notice the difference. Do you have a freind that has a fbody you can compair the brake pedal pressure with? I might be way off base, but if the brake booster was bad or going bad due to a leaky diaghram, you might have a large enough vacuum leak that while sitting still or while under a load the vent control vacuum is low enough to allow the door to move to blow air out the floor vent. I have seen this on older carbed cars. What you can do is run the car for a minute and then shut it off and let it sit for an hour or so. Then pull the hose with check out of the booster. If it still had vacuum on it it is probably ok, if it comes out easy like it had no vacuum then i bet the diaghram is crackked and you have a bad leak there causing this. I do not know how the PCM would know there is a problem in the booster, but maybe the booster is causing enough issue for the PCM to see something is not right with the brake system itself.

Just a wild thought of something to check.

brianfromhawaii

iTrader: (3)

great theory, but the brakes are perfect. thanks for the idea though!

brianfromhawaii

iTrader: (3)

i didnt get anything from you?

2001NBMZ28

Did you look at the check valve near the PCM too? There's also a vacuum feed line that runs to the vacuum storage tank on the passenger side towards the battery under the car. Might be what coD is referring to also.

brianfromhawaii

iTrader: (3)

yes i checked there also. i am thinking its a problem with the switches, i have an extra set i can try