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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 1165 (Engine Controls Diagnosis - 3.6L (Ly7) (DTC P0135 To DTC P0420)) >> Diagnostic Trouble Codes >> DTC P0201-P0206 >> Test Description

Test Description

WARNING: This page is about a different car, the 2004 Buick Rendezvous. 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. 2:  This step verifies that the condition is present.
  2. 3:  This step determines if there is condition with the ignition 1 voltage supply circuit. The fuel injectors for each bank of the engine are fused separately. If all the fuel injector open DTCs set for one bank of the engine, there is a condition with one of the ignition 1 voltage supply circuits.
  3. 5:  This step verifies that the ECM is able to control the fuel injector.
  4. 6:  This step tests if the feedback voltage circuit within the ECM is providing the correct voltage. This feedback voltage is used for determining if the fuel injector control circuit is open, shorted to a ground, or shorted to a voltage.
DTC P0201-P0206

Step Action Values Yes No
Schematic Reference:  Engine Controls Schematics 
Connector End View Reference:  Engine Control Module (ECM) 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 
  1. Turn ON the ignition, with the engine OFF.
  2. Clear the DTCs with a scan tool.
  3. Start the engine.
  4. Observe the DTC Info with a scan tool.
Does DTC P0201, P0202, P0203, P0204, P0205, or P0206 set?		 - Go to Step 3  Go to Step 4 
3  Are DTCs P0201, P0203, and P0205 set at the same time, or are DTCs P0202, P0204, and P0206 set at the same time? - Go to Step 15  Go to Step 5 
4
  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 5  Go to Diagnostic Aids
5 
  1. Turn OFF the ignition.
  2. Disconnect the fuel injector multi-way harness connector.
    3. IMPORTANT: Disconnecting the multi-way harness connector causes P0201-P0206 fuel injector circuit open DTCs to set.
  3. Probe the appropriate fuel injector control circuit, engine control module (ECM) side of harness, with a test lamp connected to B+.
  4. Crank the engine.
Does the test lamp flash while cranking the engine?		 - Go to Step 6  Go to Step 7 
6 
  1. Turn ON the ignition, with the engine OFF.
  2. Measure the voltage between the control circuit of the fuel injector, ECM side of harness, and the ECM housing with a DMM.
Is the voltage within the specified range?		 2.6-4.6 V Go to Step 8  Go to Step 17 
7 Test the control circuit of the fuel injector for an open or for high resistance between the multi-way harness connector and the ECM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 18  Go to Step 13 
8 Probe the ignition 1 voltage supply circuit, ECM side of harness, with a test lamp connected to the ECM housing.
Does the test lamp illuminate?		 - Go to Step 9  Go to Step 15 
9 Test for continuity between the ignition 1 voltage supply circuit and the appropriate fuel injector control circuit, fuel injector side of harness, at the multi-way harness connector with a DMM.
Does the DMM indicate OL?		 - Go to Step 10  Go to Step 14 
10
  1. Remove the upper intake. Refer to Intake Manifold Replacement - Upper in Engine Mechanical - 3.6L (LY7).
  2. Test the control circuit of the fuel injector for an open between the multi-way harness connector and the fuel injector connector. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 18  Go to Step 11 
11 Test the ignition 1 voltage supply circuit of the affected fuel injector for an open between the fuel injector and the splice. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 18  Go to Step 12 
12 Test for an intermittent and for a poor connection at the fuel injector. 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 18  Go to Step 16 
13 Test for an intermittent and for a poor connection at the ECM. 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 18  Go to Step 17 
14 Repair the poor connection at the fuel injector harness multi-way harness connector. Refer to Connector Repairs in Wiring Systems.
Did you complete the repair?		 - Go to Step 18  -
15
  1. Repair the ignition 1 voltage supply circuit of the fuel injector for an open or for an intermittent short to ground. Refer to Wiring Repairs in Wiring Systems.
  2. Replace the fuse if necessary.
Did you complete the repair?		 - Go to Step 18  -
16 Replace the fuel injector. Refer to Fuel Injectors and Fuel Rail Replacement .
Did you complete the replacement?		 - Go to Step 18  -
17 Replace the ECM. Refer to Engine Control Module (ECM) Replacement .
Did you complete the replacement?		 - Go to Step 18  -
18
  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 19 
19 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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