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Old 08-27-2004, 12:06 PM   #1
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My ambient temp is no longer displayed. I'll I get are three dashes.
I replaced the sensor to no avail. While I'm waiting on my new service manual, any ideas?
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Old 08-27-2004, 01:33 PM   #2
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The wiring to the sensor may have a short in it.
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Old 08-27-2004, 02:50 PM   #3
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I already checked that. No such luck. I need the pin out from the connector on the back of the HVAC module to the sensor if anyone has it.
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Old 08-27-2004, 02:57 PM   #4
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I already checked that. No such luck. I need the pin out from the connector on the back of the HVAC module to the sensor if anyone has it.
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Old 08-27-2004, 05:22 PM   #5
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There are a few things that can cause this besides the ambient temp sensor.
Lets first ensure the sensor is good.
Measure the resistance of the sensor it should be
77*F 970ohms min to 1020ohms. depending on your outside temp this should be close.

The other two things that effect this are the Vehicle speed sensors (to compensate the temp. sensor) and engine coolant temperature sensor.
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Old 08-27-2004, 05:51 PM   #6
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Just got a brand new sensor.
How are all the other tidbits integrated?
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Old 08-27-2004, 06:22 PM   #7
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Ambient Outside Air Temperature Sensor Description
This sensor is located in front of the radiator. The ambient temperature sensor is a temperature-sensitive resistor whose resistance varies inversely with temperature. As air temperature increases, resistance decreases. As air temperature decreases, resistance increases. The instrument panel integration module (IPM) monitors the ambient temperature signal and uses this information to display outside temperature on the driver information center and helps determine command signals.

During periods of city traffic and idle conditions engine heat can surround the area of the ambient temperature sensor and cause temperature readings that are higher than the actual ambient air temperature. To help eliminate these false readings programming techniques are used to minimize unwanted temperature variations.

A temperature memory feature is used in the IPM ambient temperature programming to help provide greater accuracy under engine restart conditions. If engine coolant temperature is less than 10C (50F) above the ambient temperature sensor reading, or a two-hour ignition off timer has expired then the actual sensed ambient temperature is displayed. However, if engine coolant is greater than 10C (50F) above the sensor reading, memorized ambient temperature is displayed. This is the displayed temperature sensed when the engine was previously operating. At vehicle speeds greater than 32 kmH (20 mph) the ambient temperature display may be allowed to increase, but only after a built-in 80-second time delay which allows for ambient air to cool the sensor. The 80-second time delay starts when vehicle speed reaches or maintains at least 32 kmH (20 mph). If the sensor reading is ever less than the displayed value or if the vehicle speed is 72 kmH (45 mph) or greater there is no delay and ambient temperature changes are displayed as rapidly as possible.

The scan tool is able to provide an instance temperature update.
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Old 08-27-2004, 08:38 PM   #8
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IE. get a scan tool.
From reading I'm assuming the temp sensor goes into the pcm and the rest of the math is soft. Cool.
You wouldn't know the pinout for that would you?
Sorry to be a bother, but I hate broken things.
Hopefully my manual with schems. and all will arrive soon.
Looks like a scantool should be looked into as well.
You are the man.
Thank you.
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Old 08-27-2004, 09:10 PM   #9
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No bother at all, I enjoy this stuff, up untill you asked I never knew either how it all worked together, thats the beauty of a forum

I'll look for a pin out....might take a bit, stay tunned.
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