Dash Reset -- on its own!

[Vettelt193]

My Dad has a 98 Pace Car, about 20k miles. Since he bought the car, every once in a while the dash would reset... basically, the gas mileage would go back to 0 etc., like the battery was disconnected. There doesn't seem to be any set reason for when or why it happens. It doesn't happen all the time, just every once in a while... He knows when it happens because the display goes back to the odometer, which he never looks at during normal driving. Has anyone else had this problem? the Chevy dealer has been no help at all. They put in two new batteries and new battery cables... any ideas?

 

[c4c5specialist]

Hi there,
Please retrieve the codes from the IPC, and post up what they are.
Besttoyou,c4c5

 

[Vettelt193]

What is the best way to get the codes of the car? Do I need to purchase a reader or is there a way to get them without one? Thanks for your help in advance.

 

[c4c5specialist]

Hi there,
You can start the car, and reset all messages.
Then, when you have a blank screen, hold the #4 button on the DIC, while pushing #1 four times.
Remember to have a pen and paper ready, because the codes will come fast.
Then, post the codes.
Besttoyou, c4c5

 

[Vettelt193]

Ok, here are the codes... (finally) There are two of them, under 998VAC (i could be wrong on this one, I had a hard time hearing the message... unfortunately the car is a few hundred miles away from me) B0361 and B0441... make any sense?

 

[c4c5specialist]

Hi there,
Were these the only codes listed????
c4c5

 

[Vettelt193]

that was it, My Dad got the codes off the car, he said those were the only ones... The Car has been into chevy for the problem multiple times with no luck... The corvette tech that worked on it is excellent and could not find the problem. He tried changing the battery and battery cables... He kept thinking it was battery related. It is a tough one to track down because it doesn't happen all of the time. thanks for your help, oh, and what did those codes translate to?

 

[John L]

Is your car experiencing dual zone a/c problems? Those codes indicate that your left temperature actuator is malfunctioning.

B0441 = Left actuator out of range

B0361 = Left actuator feedback short to ground

I'd try clearing the codes and see if they come back. Also, check if those codes are displaying the letters "H" or "C" or both after the numeric characters. An "H" means History, incicating a past consition which has occurred in the last 50 ignition cycles and a "C" means a Current condition.

Anyway, these codes have nothing to do with the resetting of your mileage or fuel state information. 99 HVAC = module 99, heating, ventilation and air conditioning.

 

[Vettelt193]

thanks for the info.. I am going home today, I will look at the codes myself to see what they are... These A/C codes could be why I hate the C5 A/C system... I can never seem to get the f!@#$&^ thing to work right... All I ask for is cold air, and I swear it is like you have to have training to work the A/C:confused On My '96 you just set a temperature and it blows cold.

Also, do you think the left actuator short to ground error is the problem with the whole thing? Could it be shorting out just enough to get the dash to reset? The problem really seems like a short somewhere... Do you know where I would look for this ground wire?

 

[John L]

I think that these codes mean that your driver side dual zone a/c temperature actuator/motor is acting up or has totally failed. You can check it easily by simply selecting the coldest setting by turning the temp control knob to the left until the numbers on the display reach their lowest point. See if it blows good and cold. Then turn the knob to the right until the display reads as high as it will go and see if the air starts blowing hot. If you can't get the temperature to change no matter where you set the knob, then the actuator is bad.

My passenger side temp actuator failed and I was getting similar codes to yours. The only difference was that my codes were for the passenger side. The vents on that side always blew lukewarm air, (while the driver side blew cold) no matter where I had the passenger side control knob set. I had to change the actuator/motor on that side to fix it. Changing these actuators is a major pain and very time consuming as in my case the center console, glove compartment, passenger side airbag and the dash had to come out in order to get to the part. In your situation, if the part is bad, I believe that it is located behind the instrument cluster so the driver side knee bolster, the dash and probably the instrument cluster would have to come out to get to it.

If you are having a/c trouble you can try to get the actuators to reset the temp doors by removing fuse # 27 from the passenger side footwell electrical center fuse box (while the system is operating) for a few minutes and then reinserting it. This procedure causes the BCM to perform a HVAC diagnostic. The BCM (Body Control Module) sends a signal to the HVAC module to cycle all of the temp doors through their complete traverse, from full hot to full cold. This will usually unstick an obstinate door if that is the trouble. If that doesn't work, then changing the actuator is usually the nex step.

And I doubt very much if any of this has anything to do with your instrumentation resetting problem. I think that they must be different issues. But with the C5, who knows?

 

[Vettelt193]

A/C works fine... blows cold.. what I can't stand about it is the delay of the fan... I want to turn on the air, and have it work now, not in 5 minutes (ok I am exaggerating, but it feels like it when it is hot outside!)

Yes, who knows on the C5 what the heck the problem is... i just hope it doesn't get worse.... as long as it doesn't, we will live with it

 

[John L]

If you're getting a delay from the time you activate the system until it comes on, then that is probably the a/c control head acting up or an outside air temp sensor failure. That is much easier to deal with than a temperature actuator/motor. At least the control head and the sensor are easy to get to, right there below the radio, and the sensor is beneath the radiator shroud on the pass side. If either one is shorting, that could maybe also be affecting some of your other dash readings. Is your outside temp sensor recording the correct outside temperature on the display? If it is reading lower that the actural outside temp, this could cause a delay in your system coming on to cool. It may eventually prevent it from coming on at all.