R: Glow Plug Lamp (GPL)
Introduction
Introduction
1996 PCED OBDI | SECTION 18: Diesel Diagnosis — 7.3L DI Engine |
R: Glow Plug Lamp (GPL) Introduction | R: Pinpoint Tests |
Glow Plug Relay — A relay that controls the current flow to the glow plugs. Glow plug relay ON time is controlled by the powertrain control module (PCM) and is a function of engine oil temperature, barometric pressure and battery voltage. Glow plug ON time normally varies between 10 to 120 seconds.
Glow Plug WAIT TO START Lamp — A lamp to indicate to the operator when the glow plugs have been on long enough to crank the engine. It is controlled by the PCM. WAIT TO START lamp ON time is a function of engine oil temperature, barometric pressure and battery voltage. ON time normally varies between 1 to 10 seconds. Note: WAIT TO START lamp ON time is independent from glow plug relay ON time.
An open or shorted to ground glow plug relay or WAIT TO START lamp circuit can be detected by an on-demand output circuit check performed during the KOEO standard test.
Glow plug and glow plug harness problems cannot be detected by the PCM.
Do not perform any voltage checks with the engine running; 115 v DC at 10 amps present on injector circuits.
You should enter this pinpoint test only when directed here from symptom flowcharts.
This pinpoint test is intended to diagnose only the following:
The glow plugs are energized during and after the WAIT TO START lamp is on. When the WAIT TO START lamp goes off, the engine is ready to be started.
0381 = Glow plug indicator circuit malfunction.
| R: Pinpoint Tests |