K 3500 Truck 4WD V8-6.6L DSL Turbo VIN 1 (2001)
Ignition Relay: Testing and Inspection
IGNITION RELAY DIAGNOSIS
CIRCUIT DESCRIPTION
The ignition relay supplies ignition voltage to the following components:
^
The glow plugs
^
The Fuel Injection Control Module (FICM)
^
The Engine Control Module (ECM)
^
The fuel pressure regulator
^
The Mass Air Flow (MAF) sensor
^
The fuel heater
^
The A/C compressor relay
^
The daytime running lamps
^
The rear defogger
DIAGNOSTIC AIDS
If the IGN relay fails open:
^
The scan data WILL be available.
^
The vehicle WILL crank no start.
^
The dash indicator lights WILL illuminate.
TEST DESCRIPTION
Steps 1-8
