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Home >> Hummer >> 2008 >> H2 4D Utility Wagon >> Repair and Diagnosis >> External Pages >> Different car >> Section 53 (Engine Controls And Fuel - 6.0L - DTC P0030 To DTC P0140) >> DTC P0030 or P0050 >> 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 number below refers to the step number on the diagnostic table.

  1. 7:  With no fault present, the test lamp will blink once per second.
DTC P0030 or P0050

Step Action Value(s) Yes No
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module Connector End Views
1 Did you perform the Diagnostic System Check - Vehicle? - Go to Step 2  Go to Diagnostic System Check - Vehicle
2
IMPORTANT: Whenever the heated oxygen sensor (HO2S) heaters are commanded ON with a scan tool, they will continue to be pulsed ON once per second until the ignition is turned OFF for 30 seconds.
  1. Turn ON the ignition, with the engine OFF.
  2. Command the heated oxygen sensor (HO2S) heaters ON with a scan tool.
  3. Wait 15 seconds to allow the HO2S heater current to stabilize.
  4. Observe the affected HO2S Heater Current parameter with a scan tool.
Is the HO2S Heater Current parameter within the specified range?		 0.25-3.125 A Go to Step 3  Go to Step 4 
3
  1. Observe the Freeze Frame/Failure Records for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition?		 - Go to Step 4  Go to Testing for Intermittent Conditions and Poor Connections
4 Inspect the O2A or O2B fuse.
Is the O2A or O2B fuse open?		 - Go to Step 5  Go to Step 6 
5 Test the ignition 1 voltage circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 20  Go to Step 8 
6
  1. Disconnect the affected HO2S.
  2. Turn ON the ignition, with the engine OFF.
  3. Probe the ignition 1 voltage circuit of the HO2S harness connector on the engine harness side with a test lamp that is connected to a good ground. Refer to Probing Electrical Connectors .
Does the test lamp illuminate?		 - Go to Step 7  Go to Step 17 
7 
IMPORTANT: The test lamp may blink prior to commanding the heaters ON. This is because the heaters were commanded ON in a previous step. To command the heaters OFF, turn OFF the ignition for 30 seconds.
  1. Connect a test lamp between the ignition 1 voltage circuit of the HO2S harness connector on the engine harness side and the HO2S heater low control circuit of the HO2S harness connector on the engine harness side.
  2. Command the HO2S heaters ON with a scan tool.
Does the test lamp blink once per second?		 - Go to Step 9  Go to Step 10 
8
IMPORTANT: Perform the following test on all HO2S which are supplied voltage by the suspect circuit.
Test the ignition 1 voltage circuit on the sensor side of the HO2S connector for a short to ground. Refer to Circuit Testing .Is any sensor shorted to ground?		 - Go to Step 18  Go to Testing for Intermittent Conditions and Poor Connections
9 Measure the resistance of the following circuits with a DMM:
  • The HO2S heater low control circuit
  • The ignition 1 voltage circuit

Refer to Circuit Testing .
Is the resistance of either circuit more than the specified value?		 3 Ω Go to Step 16  Go to Step 14 
10 Is the test lamp on steady? - Go to Step 11  Go to Step 12 
11 Test the HO2S heater low control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 20  Go to Step 15 
12 Test the HO2S heater low control circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 20  Go to Step 13 
13 Test the HO2S heater low control circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 20  Go to Step 15 
14 Test for shorted terminals and for poor connections at the HO2S. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?		 - Go to Step 20  Go to Step 18 
15 Test for shorted terminals and for poor connections at the powertrain control module (PCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?		 - Go to Step 20  Go to Step 19 
16 Repair the circuit with high resistance. Refer to Wiring Repairs .
Did you complete the repair?		 - Go to Step 20  -
17 Repair the open or high resistance in the ignition 1 voltage circuit. Refer to Wiring Repairs .
Did you complete the repair?		 - Go to Step 20  -
18 Replace the affected HO2S. Refer to the following:
Did you complete the replacement?		 - Go to Step 20  -
19 Replace the PCM. Refer to Control Module References for replacement, setup, and programming.
Did you complete the replacement?		 - Go to Step 20  -
20
  1. Replace the O2A or O2B fuse, if necessary.
  2. Clear the DTCs with a scan tool.
  3. Turn OFF the ignition for 30 seconds.
  4. Start the engine.
  5. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition?		 - Go to Step 2  Go to Step 21 
21 Observe the Capture Info with a scan tool.
Are there any DTCs that have not been diagnosed?		 - Go to Diagnostic Trouble Code (DTC) List - Vehicle System OK
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