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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 1712 (HVAC Systems - Automatic) >> Diagnostic Information and Procedures >> DTC B0414 >> Test Description

Test Description

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

  1. 2:  This step determines if the air temperature door is within a known calibration range that is stored in the HVAC control module.
DTC B0414

Step Action Values Yes No
Schematic Reference:  HVAC Schematics  
1 Did you perform the HVAC Diagnostic System Check? - Go to Step 2  Go to Diagnostic System Check - HVAC Systems - Automatic 
2 
  1. Install the scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With the scan tool, observe the Mix Door Max Position data parameter and the Mix Door Min Position data parameter in the Primary ECC Data list.
  4. Subtract the Mix Door Min Position from the Mix Door Max Position.
Does the result of the calculation indicate that the actual travel of the air temperature actuator is within the specified range?		 64-216 Counts Go to Step 3  Go to Step 8 
3
  1. With the scan tool, command the air temperature actuator from HOT (Off) to COLD (On).
  2. With the scan tool, observe the Air Mix Door Actual data parameter in the Primary ECC data list.
Does the scan tool indicate that the Air Mix Door Actual data parameter is within the specified range?		 5-250 Counts Go to TESTING FOR INTERMITTENT AND POOR CONNECTIONS Go to Step 4 
4 Test the ground circuit of the air temperature actuator for an open. Refer to CIRCUIT TESTING and WIRING REPAIRS .
Did you find and correct the condition?		 - Go to Step 13  Go to Step 5 
5 Test the 5 volt reference circuit of the air temperature actuator for a short to ground or short to voltage. Refer to CIRCUIT TESTING and WIRING REPAIRS .
Did you find and correct the condition?		 - Go to Step 13  Go to Step 6 
6 Test the air temperature door position signal circuit of the air temperature actuator for an open, high resistance, short to ground or short to voltage. Refer to CIRCUIT TESTING and WIRING REPAIRS .
Did you find and correct the condition?		 - Go to Step 13  Go to Step 7 
7
IMPORTANT: The air temperature actuator connector and the HVAC control module connector must be connected to correctly perform test.
  1. Turn ON the ignition, with the engine OFF.
  2. With the scan tool, observe the Air Mix Door Actual data parameter in the Primary ECC Data list.
  3. Connect a 3-amp fused jumper wire between the air temperature actuator door control circuit and the 5-volt reference circuit of the air temperature actuator. This drives the actuator to the full COOL position.
  4. Remove and reconnect the jumper wire between the air temperature actuator door control circuit and the ground circuit of the air temperature actuator. This drives the actuator to the full HOT position.
Does the air temperature actuator drive shaft rotate and do the counts change?		 - Go to Step 10  Go to Step 9 
8 Inspect the air temperature door and the air temperature actuator for the following:
  • Incorrectly installed air temperature actuator.
  • Broken or binding linkages or air temperature door.
  • Obstruction that prevents the air temperature door from operating within it's full range of motion.

Did you find and correct the condition?		 - Go to Step 13  Go to Diagnostic Aids
9 Inspect for poor connections at the harness connector of the air temperature actuator. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS and CONNECTOR REPAIRS .
Did you find and correct the condition?		 - Go to Step 13  Go to Step 11 
10 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 13  Go to Step 12 
11
IMPORTANT: Perform the recalibration for the air temperature actuator.
Replace the air temperature actuator. Refer to AIR TEMPERATURE ACTUATORS .Did you complete the replacement?		 - Go to Step 13  -
12
IMPORTANT: Perform the recalibration for the HVAC control module.
Replace the HVAC control module. Refer to HVAC Control Module Replacement .Did you complete the replacement?		 - Go to Step 13  -
13
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC reset?		 - Go to Step 2  System OK
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