HVAC display?
Thread Starter
Instructor
Joined: Feb 2006
Posts: 127
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From: El Segundo CA
HVAC display?
The HVAC digital display on my 02 C5 Z06 is only reads 69 degrees. It seems to be locked at this temp and will not reflect outside/inside changes in temps regardless of the chages. Does this mean the unit needs to be replaced completely or am I simply not properly programmed with settings?
Any assistance is appreciated, thanx!
Any assistance is appreciated, thanx!
Safety Car
Joined: Aug 2000
Posts: 4,933
Likes: 30
From: San Rafael CA
69 is the default temperature if the wiring to the OAT (Outside Air Temp) sensor becomes disconnected, or if the sensor fails. At the bottom of this post is a drawing of where the sensor is located. Check the connector to the sensor, if the wiring is good then 99 percent chance it is the outside air temperature (OAT) sensor. New one is GM part number 10248414 ... GM list price is $10.89 ... so not exactly a budget breaker.
If this helps ... from another post .....
Disconnect the sensor. You should get DTC B0333 Outside Air Temp Sensor Open, and the temp display should default to 69*F. This would tell you that there are no shorts in the wiring harness/connector.
Short the sensor connector - this won't blow anything. You should get DTC B0332 Outside Air Temp Sensor Short to Ground, and the temp display should default to 69*F. This will confirm that there are no random impedances in the circuit.
Measure the impedance of the sensor itself. At 68*F, it should measure 12,493 ohms. At 86*F/8,056 ohms, 104*F/5327 ohms. That should be enough to verify it's within its expected range
Also ... IMPORTANT .... You need to drive the car after you replace the sensor for AT LEAST 2 minutes for the system to read the new sensor. Otherwise, after you replace the sensor the temperature displayed, until you drive for a few minutes, is what was "in memory" when the engine last shut off.
The OAT is attached to the frame rail in the engine compartment .... on the passenger side .... low down and forward under the headlights. When you get the new one look for its partner ... it's a 5 minute job .... max.
If this helps ... from another post .....
Disconnect the sensor. You should get DTC B0333 Outside Air Temp Sensor Open, and the temp display should default to 69*F. This would tell you that there are no shorts in the wiring harness/connector.
Short the sensor connector - this won't blow anything. You should get DTC B0332 Outside Air Temp Sensor Short to Ground, and the temp display should default to 69*F. This will confirm that there are no random impedances in the circuit.
Measure the impedance of the sensor itself. At 68*F, it should measure 12,493 ohms. At 86*F/8,056 ohms, 104*F/5327 ohms. That should be enough to verify it's within its expected range
Also ... IMPORTANT .... You need to drive the car after you replace the sensor for AT LEAST 2 minutes for the system to read the new sensor. Otherwise, after you replace the sensor the temperature displayed, until you drive for a few minutes, is what was "in memory" when the engine last shut off.
The OAT is attached to the frame rail in the engine compartment .... on the passenger side .... low down and forward under the headlights. When you get the new one look for its partner ... it's a 5 minute job .... max.
Thread Starter
Instructor
Joined: Feb 2006
Posts: 127
Likes: 0
From: El Segundo CA
You (BlackZ06) are a good man and a technical scholar...found the problem thru your post!!! Easy fix and now motoring with the wealth of knowing my internal/external variation in temps. 
69 is the default temperature if the wiring to the OAT (Outside Air Temp) sensor becomes disconnected, or if the sensor fails. At the bottom of this post is a drawing of where the sensor is located. Check the connector to the sensor, if the wiring is good then 99 percent chance it is the outside air temperature (OAT) sensor. New one is GM part number 10248414 ... GM list price is $10.89 ... so not exactly a budget breaker.
If this helps ... from another post .....
Disconnect the sensor. You should get DTC B0333 Outside Air Temp Sensor Open, and the temp display should default to 69*F. This would tell you that there are no shorts in the wiring harness/connector.
Short the sensor connector - this won't blow anything. You should get DTC B0332 Outside Air Temp Sensor Short to Ground, and the temp display should default to 69*F. This will confirm that there are no random impedances in the circuit.
Measure the impedance of the sensor itself. At 68*F, it should measure 12,493 ohms. At 86*F/8,056 ohms, 104*F/5327 ohms. That should be enough to verify it's within its expected range
Also ... IMPORTANT .... You need to drive the car after you replace the sensor for AT LEAST 2 minutes for the system to read the new sensor. Otherwise, after you replace the sensor the temperature displayed, until you drive for a few minutes, is what was "in memory" when the engine last shut off.
The OAT is attached to the frame rail in the engine compartment .... on the passenger side .... low down and forward under the headlights. When you get the new one look for its partner ... it's a 5 minute job .... max.
If this helps ... from another post .....
Disconnect the sensor. You should get DTC B0333 Outside Air Temp Sensor Open, and the temp display should default to 69*F. This would tell you that there are no shorts in the wiring harness/connector.
Short the sensor connector - this won't blow anything. You should get DTC B0332 Outside Air Temp Sensor Short to Ground, and the temp display should default to 69*F. This will confirm that there are no random impedances in the circuit.
Measure the impedance of the sensor itself. At 68*F, it should measure 12,493 ohms. At 86*F/8,056 ohms, 104*F/5327 ohms. That should be enough to verify it's within its expected range
Also ... IMPORTANT .... You need to drive the car after you replace the sensor for AT LEAST 2 minutes for the system to read the new sensor. Otherwise, after you replace the sensor the temperature displayed, until you drive for a few minutes, is what was "in memory" when the engine last shut off.
The OAT is attached to the frame rail in the engine compartment .... on the passenger side .... low down and forward under the headlights. When you get the new one look for its partner ... it's a 5 minute job .... max.
