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Home >> GMC >> 2003 >> Safari Van Cargo, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 1558 (Engine Controls And Fuel - 3.5L (L66) - Troubleshooting & Diagnosis) >> Electronic Ignition (EI) System Diagnosis >> Test Description

Test Description

WARNING: This page is about a different car, the 2007 Saturn Vue. 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:  If the PCM does not detect a signal from either CKP sensor, the engine will not start. Damage wiring or a sensor that is disconnect causes this condition. If an engine speed is observed, there is no voltage available to the ignition coils. An open fuse in the supply circuit causes a no start and no communication with the scan tool.
  2. 5:  This step is tests for a condition with the control circuit of the ignition coil. If the voltage is not within the specified range, There is a condition with the control circuit of the ignition coil.
  3. 16:  After replacing the PCM, a new minimum throttle position and idle speed must be established.
Electronic Ignition (EI) System Diagnosis

Step Action Values Yes No
Schematic Reference:  Engine Controls Schematics 
Connector End View Reference:  Powertrain Control Module Connector End Views  or  Engine Controls Connector End Views 
1 Did you perform the Diagnostic System Check - Vehicle? - Go to Step 2  Go to Diagnostic System Check - Vehicle
2
IMPORTANT: This diagnostic procedure only diagnosis an inoperative ignition coil or a no start condition.
Were you sent here from Engine Cranks but Does Not Start?
- Go to Step 4  Go to Step 3 
3 Were you sent here from DTC P0301-P0306? - Go to Step 5  Go to DTC P0301-P0306 or Engine Cranks but Does Not Run 
Crank the engine over for 10 seconds, while you observe the engine speed parameter with a scan tool.
Is engine speed displayed on the scan tool?
- Go to Step 12  Go to Step 13 
  1. Turn OFF the ignition.
  2. Disconnect the ignition coil from the cylinder that is misfiring.
  3. Turn ON the ignition, with the engine OFF.
  4. Measure the voltage between the ignition control circuit of the ignition coil and B+ with a DMM.
Is the voltage within the specified range?
6.5-7.5 V Go to Step 6  Go to Step 8 
6 Probe the ignition 1 voltage circuit of the ignition coil with a test lamp connected to a good ground.
Does the test lamp illuminate?
- Go to Step 7  Go to Step 11 
7 Probe the ground circuit of the ignition coil with a test lamp connected to B+.
Does the test lamp illuminate?
- Go to Step 9  Go to Step 14 
8 Test the control circuit of the ignition coil for an open, short to ground, short to voltage, or for high resistance. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?
- Go to Step 17  Go to Step 10 
9 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 .
Did you find and correct the condition?
- Go to Step 17  Go to Step 15 
10 Test for an intermittent and for a poor connection at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?
- Go to Step 17  Go to Step 16 
11
  1. Repair the ignition 1 voltage circuit of the ignition coil for one of the following conditions:
    • For an open
    • For a short to ground
    • For high resistance

      Refer to Wiring Repairs .

  2. Replace the fuse if necessary.
Did you complete the repair?
- Go to Step 17  -
12 Repair the open ignition 1 voltage circuit between the splice pack 113 and the fuse. Refer to Wiring Repairs .
Did you complete the repair?
- Go to Step 17  -
13 Repair the damage circuits of the crankshaft position (CKP) sensor or connect the CKP sensor. Refer to Wiring Repairs .
Did you complete the repair?
- Go to Step 17  -
14 Repair the open ground circuit of the ignition coil. Refer to Wiring Repairs .
Did you complete the repair?
- Go to Step 17  -
15 Replace the ignition coil. Refer to the appropriate procedure:
Did you complete the replacement?
- Go to Step 17  -
16 
  1. Replace the PCM. Refer to Powertrain Control Module Replacement .
  2. Perform the idle learn procedure. Refer to Idle Learn .
Did you complete the replacement?
- Go to Step 17  -
17 Operate the vehicle in order to verify the repair
Does a driveability condition still exist?
- Go to Step 2  Go to Step 18 
18 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