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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 1350 (Engine Control System (Troubleshooting & Diagnosis) -- 1.8L (LNK)) >> Troubleshooting >> Ignition Relay Diagnosis >> Test Description

Test Description

WARNING: This page is about a different car, the 2004 Pontiac Vibe. 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. 1:  The Diagnostic System Check-Engine Controls prompts the technician to complete some basic checks and store the Freeze Frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.
  2. 6:  This step will verify the ground path for the EFI relay circuit.
Ignition Relay Diagnosis

Step Action 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 Test for an open in the EFI fuse.
Was an open fuse found?		 Go to Step 10  Go to Step 3 
3
  1. Turn ON the ignition, leaving the engine OFF.
  2. Remove and reinstall the EFI relay several times while listening for a clicking sound from the relay.
Did the EFI relay click when being reinstalled into the fuse block?		 Go to Step 4  Go to Step 5 
4
  1. Turn OFF the ignition.
  2. Remove the EFI relay from the Fuse Block-Underhood.
  3. Turn ON the ignition, leaving the engine OFF.
  4. Probe the fuse block side of terminal 5 using a test lamp connected to ground. Refer to the Relay Cavity Identification table in Diagnostic Aids.
Does the test lamp illuminate?		 Go to Step 11  Go to Step 7 
5 Probe terminal 1 of the EFI relay on the fuse block side using a test lamp connected to ground.
Does the test lamp illuminate?		 Go to Step 6  Go to Step 8 
6 
  1. Turn OFF the ignition.
  2. Probe terminal 2 of the EFI relay on the fuse block side using a test lamp connected to B+.
  3. Observe the test lamp.
Does the test lamp illuminate?		 Go to Step 12  Go to Step 9 
7 Repair the open or poor connection in the ignition positive voltage circuit between the EFI fuse and the EFI relay. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs in Wiring Systems.
Did you complete the repair?		 Go to Step 14  -
8
  1. Inspect for an open, a poor connection, or a short to ground in the EFI relay control circuit between the EFI relay and the PCM.
  2. Repair as necessary. Refer to Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Step 14  Go to Step 13 
9 Repair the open in the ground circuit between the EFI relay and G103. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs in Wiring Systems.
Did you complete the repair?		 Go to Step 14  -
10 Repair the short to ground in the EFI fuse circuit. Refer to Wiring Repairs in Wiring Systems.
Did you complete the repair?		 Go to Step 14  -
11
  1. Inspect the EFI relay circuit for an open or a poor connection, from terminal 3, to the component or system that is not receiving voltage. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
  2. Repair as necessary. Refer to Wiring Repairs in Wiring Systems.
Did you find and correct a wiring fault?		 Go to Step 14  Go to Step 12 
12 Replace the EFI relay.
Did you complete the replacement?		 Go to Step 14  -
13 Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement .
Did you complete the replacement?		 Go to Step 14  -
14 Operate the vehicle within the conditions under which the original concern was noted.
Does the system operate properly with no DTCs?		 System OK Go to Diagnostic Trouble Code (DTC) List
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