LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 1153 (Engine Controls - 3.6L (Ly7) (Troubleshooting & Diagnosis)) >> Troubleshooting >> Electronic Ignition (EI) System Diagnosis >> 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. 4:  The ignition coils for each bank are fused separately. If a fuse opens or the ignition 1 voltage circuit opens between the fuse and the splice, all the ignition coils for one bank of the engine would be inoperative. If the ground circuit opens at the engine block, the ignition coils would be inoperative for one bank of the engine.
  2. 5:  This step tests for an open or a high resistance in the ignition 1 voltage circuit of the ignition coil. If the DMM does not display near battery voltage there is an open or a high resistance in the circuit.
  3. 6:  This step determines if the ground circuit is open. If the circuit is open, the ignition coils would be inoperative for one bank of the engine.
  4. 7:  This step determines if the ignition 1 voltage circuit is shorted to ground. If the fuse is open, the ignition coils would be inoperative for one bank of the engine.
Electronic Ignition (EI) System Diagnosis

Step Action Value(s) Yes No
Schematic Reference:  Engine Controls Schematics 
1 Did you perform the Diagnostic System Check-Engine Controls? - Go to Step 2  Go to Diagnostic System Check - Engine Controls
2 Were you sent here from DTC P0300 or P0301-P0306? - Go to Step 3  Go to DTC P0300 or DTC P0301-P0306
3
  1. Start the engine.
  2. Allow the engine to reach operating temperature.
  3. Monitor all of the Misfire Current Counters with a scan tool. There are a total of 6 counters, 1 counter per cylinder.
Are any of the Misfire Current Counters incriminating?		 - Go to Step 4  Go to Intermittent Conditions 
4  Are all the misfire counters incriminating for one bank of the engine? - Go to Step 7  Go to Step 5 
5 
  1. Turn OFF the ignition.
  2. Disconnect the appropriate ignition coil.
  3. Turn ON the ignition, with the engine OFF
  4. Connect a test lamp between the ignition 1 voltage circuit of the ignition coil and a good ground.
  5. Measure the voltage between the probe of the test lamp and a good ground with a DMM. Refer to Measuring Voltage Drop in Wiring Systems.
Is the voltage at the specified value?		 B+ Go to Step 6  Go to Step 9 
6  Connect the test lamp between the ignition 1 voltage circuit of the ignition coil and to each ground circuit of the ignition coil.
Does the test lamp illuminate at each ground circuit?		 - Go to Step 8  Go to Step 10 
7  Test the ignition 1 voltage circuit for an open or high resistance at the splice of the affected bank of ignition coils. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 12  Go to Step 10 
8 Test for an intermittent and for a poor connection at the ignition coil. 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 12  Go to Step 11 
9
IMPORTANT: The ignition 1 voltage circuit is shared with other components. Disconnecting a component on the shared ignition 1 voltage circuit may isolate a shorted component. Review the electrical schematic and diagnose the shared circuits and components.
  1. Repair the ignition 1 voltage circuit for one of the following conditions:
    • A short to ground
    • An open
    • A high resistance

      Refer to Wiring Repairs in Wiring Systems.

  2. Replace the fuse as necessary.
Did you complete the repair?		 - Go to Step 12  -
10 Repair the open or high resistance in the ground circuit. Refer to Wiring Repairs in Wiring Systems.
Did you complete the repair?		 - Go to Step 12  -
11 Replace the ignition coil. Refer to the appropriate procedure:
Did you complete the replacement?		 - Go to Step 12  -
12
  1. Connect all disconnected components.
  2. Clear the DTCs with a scan tool.
  3. Start the engine.
  4. Monitor the misfire current counters with the scan tool.
Do any of the misfire counters increment?		 - Go to Step 2  Go to Step 13 
13 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
scientia non olet · About LEMON Manuals