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Home >> GMC >> 2003 >> Safari Van Cargo, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 1429 (HVAC Systems - Automatic) >> Diagnostic Information and Procedures >> Outside Air Temperature Display Inaccurate or Inoperative >> Test Description

Test Description

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The numbers below refer to the step numbers on the diagnostic table.

  1. 2:  If the vehicle has not been driven for at least 90 minutes you do not need to drive vehicle to update the outside air temperature display.
Outside Air Temperature Display Inaccurate or Inoperative

Step Action Yes No
Schematic Reference:  HVAC Schematics  
DEFINITION: Outside air temperature display is inaccurate and no Powertrain DTC has been set.
1 Did you perform the HVAC Diagnostic System Check? Go to Step 2  Go to Diagnostic System Check - HVAC Systems - Automatic 
2 
  1. Start the engine.
  2. Select the TEMP option.
  3. Test drive vehicle above 8 km/h (5 mph) in order for the module to update.
Does the system operate normally?		 Go to TESTING FOR INTERMITTENT AND POOR CONNECTIONS Go to Step 3 
3
  1. Turn OFF the ignition.
  2. Disconnect the outside air temperature sensor.
  3. Measure the resistance of the outside air temperature sensor. Refer to Sensor Resistance Table (Ambient and Inside Air Temp - ohms)  or Sensor Resistance Table (Upper, Lower and Aux Air Temp - ohms) .
Does the resistance measure near the specified value?		 Go to Step 4  Go to Step 6 
4 Test the outside air temperature sensor signal circuit for a short to ground, a high resistance, or an open. Refer to CIRCUIT TESTING and WIRING REPAIRS .
Did you find and correct the condition?		 Go to Step 10  Go to Step 5 
5 Test the low reference circuit for a short to ground, a high resistance, or an open. Refer to CIRCUIT TESTING and WIRING REPAIRS .
Did you find and correct the condition?		 Go to Step 10  Go to Step 7 
6 Inspect for poor connections at the harness connector of the outside air temperature sensor. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS and CONNECTOR REPAIRS .
Did you find and correct the condition?		 Go to Step 10  Go to Step 8 
7 Inspect for poor connections at the harness connector of the HVAC control module. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS and CONNECTOR REPAIRS .
Did you find and correct the condition?		 Go to Step 10  Go to Step 9 
8 Replace the outside air temperature sensor. Refer to Ambient Air Temperature Sensor Replacement .
Did you complete the replacement?		 Go to Step 10  -
9
IMPORTANT: Perform the calibration procedure for the HVAC control module
Replace the HVAC control module. Refer to HVAC Control Module Replacement .Did you complete the replacement?		 Go to Step 10  -
10 Operate the system in order to verify the repair.
Did you correct the condition?		 System OK Go to Step 3 
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