Check Glow Plug Relay
engine
Description
The engine preheat enable circuit (EPHT) is shorted when energized or open at other times, and the unit alarms only.
Activation Conditions
A problem has been detected in the engine preheat enable circuit (EPHT). If this alarm is activated when the circuit is energized, the circuit is detected shorted. If this alarm is activated at any other time, the circuit is detected open.
Unit Behavior
Alarm only.
Reset Conditions
Auto reset when circuit is normal, or alarm may be manually reset using the display mounted keys or by turning the unit off, then back on again.
Corrective Actions
1. Check EPHT Wiring: Inspect PM connector. Verify that there is no damage to modules, and no damage, moisture or corrosion in connector. 2. Check Engine Preheat Enable Circuit a. Using Component Test mode, refer to Section 5.2.4, energize engine preheat circuit. Verify that the circuit is energized and amp draw is displayed. NOTICE DO NOT leave the air intake circuit energized for the full five minutes if full amperage is shown, as the intake air heater element life will be greatly shortened. b. Check for power at PM-GP/EPH+. Must have minimum 11 VDC. If not, download data and replace Microprocessor Stepper Module. For replacement instructions refer to Section 5.5.2.