Econoline E550 V8-7.3L DSL Turbo VIN F (2002)
Glow Plug Relay: Description and Operation
California
Glow Plug Relay Control - California
The California glow plug system is composed of solid state Glow Plug Control Module (GPCM), glow plugs and the associated wiring harness. The
glow plug on-time is controlled by the Powertrain Control Module (PCM) and is a function of oil temperature, barometric pressure and battery
voltage. The PCM enables the GPCM which drives the individual glow plugs. Glow plug on-time normally varies between 1 to 120 seconds. In
addition to PCM control, the GPCM internally limits the glow plug operation to 180 seconds regardless of PCM commanded on-time. The power to
the glow plugs is provided through the GPCM solid state drivers directly from the vehicle battery. The GPCM monitors and detects individual glow
plug functionality, and the control and communication links to the PCM. The failures detected by the GPCM are passed to the PCM using a serial
communication signal on the diagnostic line.
NOTE: Wait to start lamp on-time is independent from GPCM on-time.
