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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 1442 (Engine Control System - Diagnosis - 4.2L (DTC P0507 To DTC P2176)) >> Diagnosis Information & Procedures >> DTC P1133 >> Test Description

Test Description

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

  1. 2:  When the system is operating correctly, the HO2S 1 voltage should toggle above and below the specified values. You may need to operate the vehicle within the Freeze Frame conditions and Conditions for Setting the DTC in order to duplicate the malfunction that was detected by the PCM.
  2. 4:  The specified value is what is measured on a correctly operating system.
  3. 5:  The specified value is what is measured on a correctly operating system.
DTC P1133

Step Action Values Yes No
Schematic Reference:  Engine Controls Schematics 
Connector End View Reference:  Powertrain Control Module (PCM) Connector End Views  or  Engine Controls Connector End Views 
1 Did you perform the Diagnostic System Check-Engine Controls? - Go to Step 2  Go to Diagnostic System Check - Engine Controls
2 
IMPORTANT: If any other DTCs are set except for heated oxygen sensor (HO2S) DTCs, refer to the other DTCs first before proceeding with this table.
  1. Operate the engine at normal operating temperature.
  2. Operate the engine above 1,200 RPM for 2 minutes.
  3. Observe the HO2S 1 voltage parameter with a scan tool.
Does the scan tool indicate that the HO2S 1 voltage is varying above and below the specified values?		 250-500 mV 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 Intermittent Conditions
4 
  1. Turn OFF the ignition.
  2. Disconnect the HO2S 1.
  3. Turn ON the ignition, with the engine OFF.
  4. Measure the voltage of the HO2S 1 high signal circuit on the powertrain control module (PCM) side to a good ground with the DMM.
Does the voltage measure within the specified value?		 350-550 mV Go to Step 5  Go to Step 9 
5 
  1. Turn OFF the ignition.
  2. Connect a 3-amp fused jumper wire between the HO2S 1 high signal circuit and the HO2S 1 low signal circuit.
  3. Turn ON the ignition.
  4. Monitor the HO2S 1 voltage for the sensor that applies to this DTC with the scan tool.
Does the scan tool indicate that the HO2S 1 voltage is less than the specified value?		 20 mV Go to Step 6  Go to Step 10 
6
  1. Turn OFF the ignition.
  2. Remove the 3-amp fused jumper wire.
  3. Connect a test lamp between the ignition 1 voltage circuit and a good ground. DO NOT use the HO2S 1 heater low control.
  4. Turn ON the ignition, with the engine OFF.
Does the test lamp illuminate?		 - Go to Step 7  Go to Step 11 
7
  1. Connect a test lamp between the ignition 1 voltage circuit and the HO2S 1 heater low control circuit.
  2. Turn ON the ignition, with the engine OFF.
  3. Command the HO2S 1 heater ON and OFF with the scan tool.
Does the test lamp turn ON and OFF with each command?		 - Go to Step 14  Go to Step 8 
8 Does the test lamp remain illuminated with each command? - Go to Step 12  Go to Step 13 
9 Test the HO2S 1 high signal circuit for the following conditions:
  • An open
  • High resistance
  • A short to ground
  • A short to voltage

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 19  Go to Step 16 
10 Test the HO2S 1 low signal circuit for the following conditions:
  • An open
  • A short to voltage
  • High resistance

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 19  Go to Step 16 
11
  1. Test the ignition 1 voltage circuit for the following conditions:
  2. Replace the O2 fuse if necessary.
Did you find and correct the condition?		 - Go to Step 19  Go to Step 15 
12 Test the HO2S 1 heater low control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 19  Go to Step 16 
13 Test the HO2S 1 heater low control circuit for the following conditions:
  • An open
  • A short to voltage
  • High resistance

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 19  Go to Step 16 
14
IMPORTANT: Before replacing the HO2S 1, inspect and remove any source of contamination.
Inspect for the following conditions:
  • The use of incorrect silicon RTV sealant
  • Fuel contamination
  • An exhaust leak-Refer to Exhaust Leakage in Engine Exhaust.
  • The HO2S is installed correctly
  • Damaged wiring- Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 19  Go to Step 15 
15 Inspect for poor connections at the harness connector of the HO2S 1. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 19  Go to Step 17 
16 Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 19  Go to Step 18 
17
NOTE: Refer to Heated Oxygen Sensor (HO2S) Resistance Learn Reset Notice in Cautions and Notices.
Replace the HO2S 1. Refer to Heated Oxygen Sensor Replacement - Position 1 .Did you complete the replacement?		 - Go to Step 19  -
18 Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement .
Did you complete the replacement?		 - Go to Step 19  -
19
  1. Clear the DTCs with a scan tool.
  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 2  Go to Step 20 
20 Observe the Capture Info with a scan tool.
Are there any DTCs that have not been diagnosed?		 - Go to Diagnostic Trouble Code (DTC) List System OK
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