Ignition Relay: Testing and Inspection

2006 Chevrolet Tahoe 2WD V8-5.3L VIN TSECTION Testing and Inspection


IGNITION RELAY DIAGNOSIS

CIRCUIT DESCRIPTION
The ignition relay is a normally open relay. The relay armature is held in the open position by spring tension. When the ignition switch is turned to the run or start position, current will flow through the relay coil. A wire connected to the other end of the relay coil completes the path to ground. The electomagnetic field created by the relay coil, overcomes the spring tension and moves the armature allowing the relay contacts to close. The closed relay contacts allow current to flow from the battery to the following fuses:
- The PCM 1 fuse
- The ETC/ECM fuse
- The INJ 1 fuse
- The INJ 2 fuse
- The SBA fuse, if equipped.

When the ignition switch is turned to the OFF position, the electromagnetic field collapses. This action allows the spring tension to move the armature away from the relay contacts, which interrupts current flow to the fuses.

If the ignition relay fails to close, the engine will crank, but will not run. The class 2 communications will be available with the use of a scan tool.

The ignition relay table assumes that the vehicle battery is fully charged. Refer to Battery Inspection/Test (Non-HP2) in Starting and Charging. Battery Inspection/Test

TEST

Step 1 - Step 7:




Step 8 - Step 17:




Step 18 - Step 26:




Step 27 - Step 31:




RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.