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Home >> Hummer >> 2008 >> H2 4D Utility Wagon >> Repair and Diagnosis >> External Pages >> Different car >> Section 17 (HVAC - Automatic) >> Diagnostic Information and Procedures >> DTC B0229, B0414, B0424, or B3770 >> Test Description

Test Description

WARNING: This page is about a different car, the 2007 Hummer H2. However, it is still accessible from the selected car via links, so may be relevant.

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

  1. 3:  This step tests for the proper operation of the circuit in the low voltage range.
  2. 4:  This step tests for the proper operation of the circuit in the high voltage range. If the jumper fuse opens when you perform this test, the circuit is shorted to ground.
  3. 5:  This step tests for a short to voltage in the 5-volt reference circuit.
  4. 6:  This step tests for a high resistance or for an open in the low reference circuit.
DTC B0229, B0414, B0424, or B3770

Step Action Values Yes No
Schematic Reference: HVAC Schematics 
Connector End View Reference: HVAC Connector End Views 
1 Did you perform the Diagnostic System Check - Vehicle? - Go to Step 2  Go to Diagnostic System Check - Vehicle
2
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With the scan tool, observe the appropriate Door Actual parameter in the Heating and Air Conditioning data list.
Does the scan tool indicate that the appropriate Door Actual parameter is within the specified range?		 5-250 counts Go to Diagnostic Aids Go to Step 3 
3 
  1. Turn OFF the ignition.
  2. Disconnect the appropriate HVAC door actuator.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the appropriate Door Actual parameter.
Does the scan tool indicate that the appropriate Door Actual parameter is less than the specified value?		 5 counts Go to Step 4  Go to Step 10 
4 
  1. Turn OFF the ignition.
  2. Connect a 3-amp fused jumper between the 5-volt reference circuit and the appropriate door position signal circuit of the HVAC door actuator.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the appropriate Door Actual parameter.
Does the scan tool indicate that the appropriate Door Actual parameter is greater than the specified value?		 230 counts Go to Step 5  Go to Step 8 
5 
  1. Disconnect the fused jumper.
  2. Measure the voltage between the 5-volt reference circuit and the low reference circuit of the HVAC door actuator.
Does the voltage measure less than the specified value?		 5.5 V Go to Step 6  Go to Step 7 
6 
  1. Turn OFF the ignition.
  2. Disconnect the negative battery cable.
  3. Measure the resistance from the low reference circuit of the HVAC door actuator to a good ground.
Does the resistance measure less than the specified value?		 5 Ω Go to Step 12  Go to Step 11 
7 Test the 5-volt reference circuit of the appropriate HVAC door actuator for a short to voltage. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 16  Go to Step 13 
8 Test the 5-volt reference circuit of the appropriate HVAC door actuator for a short to ground, for a high resistance, or for an open. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 16  Go to Step 9 
9 Test the appropriate door position signal circuit of the HVAC door actuator for a short to ground, for a high resistance, or for an open. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 16  Go to Step 13 
10 Test the appropriate door position signal circuit of the HVAC door actuator for a short to voltage. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 16  Go to Step 13 
11
  1. Disconnect the HVAC control module.
  2. Test the low reference circuit of the appropriate HVAC door actuator for a high resistance or for an open. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 16  Go to Step 13 
12 Inspect for poor connections at the harness connector of the appropriate HVAC door actuator. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?		 - Go to Step 16  Go to Step 14 
13 Inspect for poor connections at the harness connector of the HVAC control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?		 - Go to Step 16  Go to Step 15 
14
IMPORTANT: Perform the calibration procedure for HVAC door actuators.
Replace the HVAC door actuator. Refer to the appropriate replacement procedure:Did you complete the replacement?		 - Go to Step 16  -
15 Replace the HVAC control module. Refer to Control Module References for replacement, setup, and programming.
Did you complete the replacement?		 - Go to Step 16  -
16
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle according to the Conditions for Running in the DTC, as specified in the supporting text.
Does the DTC set again?		 - Go to Step 2  System OK
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