S: Glow Plug System
Introduction
Introduction
1997 PCED OBDII-Diesel | SECTION 5C: Pinpoint Tests |
S: Glow Plug System Introduction | S: 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 concerns cannot be detected by the PCM.
Do not perform any voltage checks with the engine running; 115v DC at 10 amps present on injector circuits.
Enter this pinpoint test only when directed here from the symptom flowcharts.
This pinpoint test is intended to diagnose only the following:
The glow plug relay control signal is used to control a relay to cycle the glow plugs for assisting engine start-up. Glow plugs will be operated at low ambient temperature and/or high altitude. Engine oil temperature, battery voltage, and barometric pressure are used to control the glow plug relay. At colder temperatures, the plugs are on longer. At high battery voltage the duty cycle is reduced to prevent plug damage. For low barometric pressure, the ON time is extended to assist start/drive-away.
On all 49 State except Econoline, do not use a shunt when monitoring circuit.
P0380 = Glow plug circuit malfunction
P1391 = 4 Glow plugs open right bank
P1392 = Glow plug circuit high input bank No. 1 (right)
P1393 = 4 Glow plugs open left bank
P1394 = Glow plug circuit high input bank No. 2 (left)
P1395 = 1 to 3 Glow plugs open right bank
P1396 = 1 to 3 Glow plugs open left bank
P1397 = System voltage out of self test range
| S: Pinpoint Tests |